{"transactions":[{"id":671383,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-09-02T00:16:27.000Z","date":"2026-08-31","kind":"sale","planned":true,"acquired":false,"shares":8103,"price":20.44,"value":165625.32,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 1, 2026."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $19.95 to $20.77 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 50,886 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), (ii) 297,110 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan (the \"Plan\"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement, and (iii) 129,870 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":477866,"source":{"system":"sec-edgar","filing":"0001470831-26-000868","document":"wk-form4_1788308184.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000868/wk-form4_1788308184.xml","form_type":"4"}},{"id":671382,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-09-02T00:16:27.000Z","date":"2026-08-28","kind":"sale","planned":true,"acquired":false,"shares":53473,"price":20.01,"value":1069994.73,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $20.00 to $20.15 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":485969,"source":{"system":"sec-edgar","filing":"0001470831-26-000868","document":"wk-form4_1788308184.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000868/wk-form4_1788308184.xml","form_type":"4"}},{"id":683808,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-08-19T00:06:54.000Z","date":"2026-08-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":22342,"price":18.49,"value":413103.58,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 112,462 shares of Series A Common Stock; (ii) 297,110 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the \"Plan\"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 129,870 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":539442,"source":{"system":"sec-edgar","filing":"0001470831-26-000843","document":"wk-form4_1787098011.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000843/wk-form4_1787098011.xml","form_type":"4"}},{"id":775358,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-05-19T00:16:06.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":22340,"price":14.38,"value":321249.2,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 93,396 shares of Series A Common Stock; (ii) 338,518 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the \"Plan\"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 129,870 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":561784,"source":{"system":"sec-edgar","filing":"0001470831-26-000461","document":"wk-form4_1779149764.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000461/wk-form4_1779149764.xml","form_type":"4"}},{"id":803010,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-04-23T00:01:18.000Z","date":"2026-04-20","kind":"sale","planned":true,"acquired":false,"shares":9623,"price":20,"value":192460.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 74,332 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), (ii) 379,922 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan (the \"Plan\"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement, and (iii) 129,870 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":584124,"source":{"system":"sec-edgar","filing":"0001470831-26-000400","document":"wk-form4_1776902476.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000400/wk-form4_1776902476.xml","form_type":"4"}},{"id":805844,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-04-18T00:14:40.000Z","date":"2026-04-15","kind":"grant","planned":false,"acquired":true,"shares":129870,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"Represents performance stock units (\"PSUs\") awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement. The PSUs will vest in up to three tranches over a two-year measurement period, subject to the achievement of specified performance targets tied to the trading price of the Series A Common Stock and the Reporting Person's continued service in the same or substantially equivalent position as the Reporting Person held as of the grant date through the applicable vesting date. Each tranche of PSUs will vest only if the average closing price of the Series A Common Stock for a period of at least sixty consecutive calendar days is at or above a specified dollar value during the applicable measurement period."},{"field":"shares","element":"transactionShares","label":"F3","text":"(continued) The stock price targets for tranches 1 through 3 are $30.00, $50.00, and $75.00 per share, respectively, subject to proportionate adjustment in the event of any stock split or other similar change in the Issuer's capital stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 83,955 shares of Series A Common Stock; (ii) 379,922 unvested RSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 129,870 unvested PSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":593747,"source":{"system":"sec-edgar","filing":"0001470831-26-000384","document":"wk-form4_1776471278.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000384/wk-form4_1776471278.xml","form_type":"4"}},{"id":805843,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-04-18T00:14:40.000Z","date":"2026-04-15","kind":"grant","planned":false,"acquired":true,"shares":151515,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Option and Incentive Plan (the \"Plan\"), each representing the contingent right to receive one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), upon vesting and settlement. The RSUs vest as follows: (i) 50% of the RSUs will vest in eight equal quarterly installments, with the first such installment vesting on May 15, 2026, and (ii) thereafter the remaining 50% of the RSUs will vest in four equal quarterly installments, subject to the Reporting Person's continued service on each such vesting date."}],"balance_after":463877,"source":{"system":"sec-edgar","filing":"0001470831-26-000384","document":"wk-form4_1776471278.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000384/wk-form4_1776471278.xml","form_type":"4"}},{"id":844161,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-03-13T23:58:56.000Z","date":"2026-03-12","kind":"sale","planned":true,"acquired":false,"shares":14366,"price":20.15,"value":289474.9,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $20.00 to $20.45 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 83,955 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 228,407 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":312362,"source":{"system":"sec-edgar","filing":"0001470831-26-000272","document":"wk-form4_1773446333.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000272/wk-form4_1773446333.xml","form_type":"4"}},{"id":858899,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-03-06T02:34:32.000Z","date":"2026-03-05","kind":"sale","planned":true,"acquired":false,"shares":15093,"price":20.16,"value":304274.88,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $20.00 to $20.63 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 98,321 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 228,407 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":326728,"source":{"system":"sec-edgar","filing":"0001470831-26-000249","document":"wk-form4_1772764470.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000249/wk-form4_1772764470.xml","form_type":"4"}},{"id":897358,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2026-02-18T21:16:27.000Z","date":"2026-02-17","kind":"exercise","planned":false,"acquired":false,"shares":11052,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":0,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11052},"source":{"system":"sec-edgar","filing":"0001470831-26-000164","document":"wk-form4_1771449384.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000164/wk-form4_1771449384.xml","form_type":"4"}},{"id":897357,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2026-02-18T21:16:27.000Z","date":"2026-02-15","kind":"exercise","planned":false,"acquired":false,"shares":11448,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,448 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":11052,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11448},"source":{"system":"sec-edgar","filing":"0001470831-26-000164","document":"wk-form4_1771449384.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000164/wk-form4_1771449384.xml","form_type":"4"}},{"id":897356,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-02-18T21:16:27.000Z","date":"2026-02-17","kind":"exercise","planned":false,"acquired":true,"shares":11052,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 113,414 shares of Series A Common Stock and (ii) 228,407 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":341821,"source":{"system":"sec-edgar","filing":"0001470831-26-000164","document":"wk-form4_1771449384.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000164/wk-form4_1771449384.xml","form_type":"4"}},{"id":897355,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-02-18T21:16:27.000Z","date":"2026-02-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":24561,"price":18.6,"value":456834.6,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":330769,"source":{"system":"sec-edgar","filing":"0001470831-26-000164","document":"wk-form4_1771449384.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000164/wk-form4_1771449384.xml","form_type":"4"}},{"id":897354,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-02-18T21:16:27.000Z","date":"2026-02-15","kind":"exercise","planned":false,"acquired":true,"shares":11448,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,448 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":355330,"source":{"system":"sec-edgar","filing":"0001470831-26-000164","document":"wk-form4_1771449384.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000164/wk-form4_1771449384.xml","form_type":"4"}},{"id":937399,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-01-16T21:04:30.000Z","date":"2026-01-15","kind":"sale","planned":true,"acquired":false,"shares":4399,"price":25.52,"value":112262.48,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.36 to $25.68 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 90,284 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 253,598 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":343882,"source":{"system":"sec-edgar","filing":"0001470831-26-000039","document":"wk-form4_1768597468.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000039/wk-form4_1768597468.xml","form_type":"4"}},{"id":937398,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2026-01-16T21:04:30.000Z","date":"2026-01-15","kind":"sale","planned":true,"acquired":false,"shares":5601,"price":26.08,"value":146074.08,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.80 to $26.73 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":348281,"source":{"system":"sec-edgar","filing":"0001470831-26-000039","document":"wk-form4_1768597468.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083126000039/wk-form4_1768597468.xml","form_type":"4"}},{"id":962176,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-12-19T21:08:00.000Z","date":"2025-12-18","kind":"sale","planned":true,"acquired":false,"shares":472,"price":30.55,"value":14419.6,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.45 to $30.63 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 100,284 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 253,598 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":353882,"source":{"system":"sec-edgar","filing":"0001470831-25-000447","document":"wk-form4_1766178477.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000447/wk-form4_1766178477.xml","form_type":"4"}},{"id":962175,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-12-19T21:08:00.000Z","date":"2025-12-18","kind":"sale","planned":true,"acquired":false,"shares":13718,"price":31.41,"value":430882.38,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.64 to $31.63 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":354354,"source":{"system":"sec-edgar","filing":"0001470831-25-000447","document":"wk-form4_1766178477.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000447/wk-form4_1766178477.xml","form_type":"4"}},{"id":965407,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-12-17T22:22:33.000Z","date":"2025-12-15","kind":"gift","planned":false,"acquired":false,"shares":8400,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents a bona fide gift of 8,400 shares of stock from the Reporting Person to a donor-advised fund."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 114,474 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 253,598 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":368072,"source":{"system":"sec-edgar","filing":"0001470831-25-000429","document":"wk-form4_1766010150.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000429/wk-form4_1766010150.xml","form_type":"4"}},{"id":991518,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-11-21T21:08:04.000Z","date":"2025-11-20","kind":"sale","planned":true,"acquired":false,"shares":4020,"price":26.97,"value":108419.4,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $26.84 to $27.34 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 122,874 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 253,598 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":376472,"source":{"system":"sec-edgar","filing":"0001470831-25-000361","document":"wk-form4_1763759281.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000361/wk-form4_1763759281.xml","form_type":"4"}},{"id":991517,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-11-21T21:08:04.000Z","date":"2025-11-20","kind":"sale","planned":true,"acquired":false,"shares":10374,"price":27.83,"value":288708.42,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $27.45 to $28.39 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":380492,"source":{"system":"sec-edgar","filing":"0001470831-25-000361","document":"wk-form4_1763759281.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000361/wk-form4_1763759281.xml","form_type":"4"}},{"id":996055,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-11-18T21:10:56.000Z","date":"2025-11-17","kind":"exercise","planned":false,"acquired":false,"shares":11074,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of 22,500 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":22500,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11074},"source":{"system":"sec-edgar","filing":"0001470831-25-000337","document":"wk-form4_1763500254.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000337/wk-form4_1763500254.xml","form_type":"4"}},{"id":996054,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-11-18T21:10:56.000Z","date":"2025-11-15","kind":"exercise","planned":false,"acquired":false,"shares":11426,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":33574,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11426},"source":{"system":"sec-edgar","filing":"0001470831-25-000337","document":"wk-form4_1763500254.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000337/wk-form4_1763500254.xml","form_type":"4"}},{"id":996053,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-11-18T21:10:56.000Z","date":"2025-11-17","kind":"exercise","planned":false,"acquired":true,"shares":11074,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 137,268 shares of Series A Common Stock and (ii) 253,598 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":390866,"source":{"system":"sec-edgar","filing":"0001470831-25-000337","document":"wk-form4_1763500254.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000337/wk-form4_1763500254.xml","form_type":"4"}},{"id":996052,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-11-18T21:10:56.000Z","date":"2025-11-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":24218,"price":28.61,"value":692876.98,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":379792,"source":{"system":"sec-edgar","filing":"0001470831-25-000337","document":"wk-form4_1763500254.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000337/wk-form4_1763500254.xml","form_type":"4"}},{"id":996051,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-11-18T21:10:56.000Z","date":"2025-11-15","kind":"exercise","planned":false,"acquired":true,"shares":11426,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":404010,"source":{"system":"sec-edgar","filing":"0001470831-25-000337","document":"wk-form4_1763500254.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000337/wk-form4_1763500254.xml","form_type":"4"}},{"id":1062117,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-18","kind":"exercise","planned":true,"acquired":false,"shares":11074,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F7","text":"Consists of 45,000 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":45000,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11074},"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1062116,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-15","kind":"exercise","planned":true,"acquired":false,"shares":11426,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":56074,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11426},"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1062115,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-18","kind":"sale","planned":true,"acquired":false,"shares":9965,"price":31.46,"value":313498.9,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F4","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $31.20 to $31.76 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Consists of (i) 113,798 shares of Series A Common Stock and (ii) 278,786 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":392584,"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1062114,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-18","kind":"exercise","planned":true,"acquired":true,"shares":11074,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":402549,"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1062113,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-15","kind":"tax_withholding","planned":true,"acquired":false,"shares":24695,"price":31.43,"value":776163.85,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":391475,"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1062112,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-08-20T00:44:24.000Z","date":"2025-08-15","kind":"exercise","planned":true,"acquired":true,"shares":11426,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":416170,"source":{"system":"sec-edgar","filing":"0001470831-25-000139","document":"wk-form4_1755650660.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000147083125000139/wk-form4_1755650660.xml","form_type":"4"}},{"id":1145719,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-15","kind":"exercise","planned":true,"acquired":false,"shares":11074,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F7","text":"Consists of 67,500 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":67500,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11074},"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1145718,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-15","kind":"exercise","planned":true,"acquired":false,"shares":11426,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":78574,"derivative":{"underlying":"Series A Common Stock","underlying_shares":11426},"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1145717,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-16","kind":"sale","planned":true,"acquired":false,"shares":9965,"price":34.85,"value":347280.25,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F4","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.50 to $35.37 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Consists of (i) 99,831 shares of Series A Common Stock and (ii) 304,913 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":404744,"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1145716,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-15","kind":"exercise","planned":true,"acquired":true,"shares":11074,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":414709,"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1145715,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-15","kind":"tax_withholding","planned":true,"acquired":false,"shares":24694,"price":34.9,"value":861820.6,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":403635,"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1145714,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-05-17T00:47:51.000Z","date":"2025-05-15","kind":"exercise","planned":true,"acquired":true,"shares":11426,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 11,426 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":428329,"source":{"system":"sec-edgar","filing":"0001835830-25-000058","document":"wk-form4_1747442865.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000058/wk-form4_1747442865.xml","form_type":"4"}},{"id":1200535,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-03-18T22:50:05.000Z","date":"2025-03-17","kind":"grant","planned":false,"acquired":true,"shares":130072,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), upon vesting and settlement. The RSUs vest as follows: (i) 50% of the RSUs will vest in eight equal quarterly installments, with the first such installment vesting on May 15, 2025, and (ii) thereafter the remaining 50% of the RSUs will vest in four equal quarterly installments, subject to the Reporting Person's continued service on each such vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 85,864 shares of Series A Common Stock and (ii) 331,039 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":416903,"source":{"system":"sec-edgar","filing":"0001835830-25-000029","document":"wk-form4_1742338198.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000029/wk-form4_1742338198.xml","form_type":"4"}},{"id":1223109,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-03-05T21:14:49.000Z","date":"2025-03-03","kind":"sale","planned":true,"acquired":false,"shares":2322,"price":38.2,"value":88700.4,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $38.05 to $38.37 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 85,864 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 200,967 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":286831,"source":{"system":"sec-edgar","filing":"0001835830-25-000025","document":"wk-form4_1741209276.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000025/wk-form4_1741209276.xml","form_type":"4"}},{"id":1223108,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-03-05T21:14:49.000Z","date":"2025-03-03","kind":"sale","planned":true,"acquired":false,"shares":3900,"price":39.26,"value":153114.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $38.94 to $39.64 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":289153,"source":{"system":"sec-edgar","filing":"0001835830-25-000025","document":"wk-form4_1741209276.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000025/wk-form4_1741209276.xml","form_type":"4"}},{"id":1260600,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-02-19T22:43:15.000Z","date":"2025-02-15","kind":"exercise","planned":false,"acquired":false,"shares":3586,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of 90,000 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":90000,"derivative":{"underlying":"Series A Common Stock","underlying_shares":3586},"source":{"system":"sec-edgar","filing":"0001835830-25-000018","document":"wk-form4_1740004987.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000018/wk-form4_1740004987.xml","form_type":"4"}},{"id":1260599,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2025-02-19T22:43:15.000Z","date":"2025-02-15","kind":"exercise","planned":false,"acquired":false,"shares":3914,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 3,914 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":93586,"derivative":{"underlying":"Series A Common Stock","underlying_shares":3914},"source":{"system":"sec-edgar","filing":"0001835830-25-000018","document":"wk-form4_1740004987.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000018/wk-form4_1740004987.xml","form_type":"4"}},{"id":1260598,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-02-19T22:43:15.000Z","date":"2025-02-15","kind":"exercise","planned":false,"acquired":true,"shares":3586,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 92,086 shares of Series A Common Stock and (ii) 200,967 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":293053,"source":{"system":"sec-edgar","filing":"0001835830-25-000018","document":"wk-form4_1740004987.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000018/wk-form4_1740004987.xml","form_type":"4"}},{"id":1260597,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-02-19T22:43:15.000Z","date":"2025-02-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":13054,"price":47,"value":613538.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":289467,"source":{"system":"sec-edgar","filing":"0001835830-25-000018","document":"wk-form4_1740004987.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000018/wk-form4_1740004987.xml","form_type":"4"}},{"id":1260596,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-02-19T22:43:15.000Z","date":"2025-02-15","kind":"exercise","planned":false,"acquired":true,"shares":3914,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 3,914 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":302521,"source":{"system":"sec-edgar","filing":"0001835830-25-000018","document":"wk-form4_1740004987.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000018/wk-form4_1740004987.xml","form_type":"4"}},{"id":1305459,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-01-11T00:02:00.000Z","date":"2025-01-07","kind":"sale","planned":true,"acquired":false,"shares":25207,"price":41.62,"value":1049115.34,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $41.22 to $41.89 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 79,642 shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 218,965 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":298607,"source":{"system":"sec-edgar","filing":"0001835830-25-000003","document":"wk-form4_1736553714.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000003/wk-form4_1736553714.xml","form_type":"4"}},{"id":1305458,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2025-01-11T00:02:00.000Z","date":"2025-01-07","kind":"sale","planned":true,"acquired":false,"shares":14793,"price":42.1,"value":622785.3,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $41.90 to $42.89 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."}],"balance_after":323814,"source":{"system":"sec-edgar","filing":"0001835830-25-000003","document":"wk-form4_1736553714.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583025000003/wk-form4_1736553714.xml","form_type":"4"}},{"id":1327002,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-12-18T21:36:18.000Z","date":"2024-12-16","kind":"exercise","planned":false,"acquired":false,"shares":101986,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"Each share of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"Each share of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of 97,500 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of the Issuer's Series B Common Stock upon vesting and settlement."}],"balance_after":97500,"derivative":{"underlying":"Series A Common Stock","underlying_shares":101986},"source":{"system":"sec-edgar","filing":"0001835830-24-000121","document":"wk-form4_1734557773.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000121/wk-form4_1734557773.xml","form_type":"4"}},{"id":1327001,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-12-18T21:36:18.000Z","date":"2024-12-16","kind":"exercise","planned":false,"acquired":true,"shares":101986,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"Each share of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 119,642  shares of Series A Common Stock and (ii) 218,965 unvested restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":338607,"source":{"system":"sec-edgar","filing":"0001835830-24-000121","document":"wk-form4_1734557773.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000121/wk-form4_1734557773.xml","form_type":"4"}},{"id":1359728,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-18","kind":"exercise","planned":true,"acquired":false,"shares":40000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F4","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F7","text":"Consists of (i) 101,986 shares of Series B Common Stock and (ii) 97,500 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":199486,"derivative":{"underlying":"Series A Common Stock","underlying_shares":40000},"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1359727,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-15","kind":"exercise","planned":true,"acquired":false,"shares":16666,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,666 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":239486,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16666},"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1359726,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-18","kind":"sale","planned":true,"acquired":false,"shares":40000,"price":34.56,"value":1382400.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F4","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.13 to $34.99  per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F6","text":"Consists of (i) 17,656 shares of Series A Common Stock and (ii) 218,965 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":236621,"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1359725,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-18","kind":"exercise","planned":true,"acquired":true,"shares":40000,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F4","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":276621,"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1359724,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-15","kind":"tax_withholding","planned":true,"acquired":false,"shares":25788,"price":35.16,"value":906706.08,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."}],"balance_after":236621,"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1359723,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-11-19T23:11:17.000Z","date":"2024-11-15","kind":"exercise","planned":true,"acquired":true,"shares":16666,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,666 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":262409,"source":{"system":"sec-edgar","filing":"0001835830-24-000113","document":"wk-form4_1732057869.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000113/wk-form4_1732057869.xml","form_type":"4"}},{"id":1421046,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-08-28T21:19:10.000Z","date":"2024-08-26","kind":"exercise","planned":true,"acquired":false,"shares":16216,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 17, 2023."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 125,768 shares of Series B Common Stock and (ii) 130,384 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":256152,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16216},"source":{"system":"sec-edgar","filing":"0001835830-24-000091","document":"wk-form4_1724879944.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000091/wk-form4_1724879944.xml","form_type":"4"}},{"id":1421045,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-28T21:19:10.000Z","date":"2024-08-26","kind":"sale","planned":true,"acquired":false,"shares":21764,"price":32.28,"value":702541.92,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 17, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $32.00 to $32.63 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 8,781 shares of Series A Common Stock and (ii) 236,962 unvested restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":245743,"source":{"system":"sec-edgar","filing":"0001835830-24-000091","document":"wk-form4_1724879944.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000091/wk-form4_1724879944.xml","form_type":"4"}},{"id":1421044,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-28T21:19:10.000Z","date":"2024-08-26","kind":"exercise","planned":true,"acquired":true,"shares":16216,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 17, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":267507,"source":{"system":"sec-edgar","filing":"0001835830-24-000091","document":"wk-form4_1724879944.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000091/wk-form4_1724879944.xml","form_type":"4"}},{"id":1431563,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-08-16T23:50:05.000Z","date":"2024-08-15","kind":"exercise","planned":false,"acquired":false,"shares":16667,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,667 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 141,984 shares of Series B Common Stock and (ii) 130,384 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":272368,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16667},"source":{"system":"sec-edgar","filing":"0001835830-24-000089","document":"wk-form4_1723852199.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000089/wk-form4_1723852199.xml","form_type":"4"}},{"id":1431562,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-16T23:50:05.000Z","date":"2024-08-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":25789,"price":31.83,"value":820863.87,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F3","text":"Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 14,329 shares of Series A Common Stock and (ii) 236,962 unvested RSUs awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":251291,"source":{"system":"sec-edgar","filing":"0001835830-24-000089","document":"wk-form4_1723852199.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000089/wk-form4_1723852199.xml","form_type":"4"}},{"id":1431561,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-16T23:50:05.000Z","date":"2024-08-15","kind":"exercise","planned":false,"acquired":true,"shares":16667,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,667 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":277080,"source":{"system":"sec-edgar","filing":"0001835830-24-000089","document":"wk-form4_1723852199.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000089/wk-form4_1723852199.xml","form_type":"4"}},{"id":1437063,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-08-09T23:31:16.000Z","date":"2024-08-09","kind":"exercise","planned":true,"acquired":false,"shares":16218,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 125,768 shares of Series B Common Stock and (ii) 163,267 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":289035,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16218},"source":{"system":"sec-edgar","filing":"0001991399-24-000004","document":"wk-form4_1723246270.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000004/wk-form4_1723246270.xml","form_type":"4"}},{"id":1437062,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-09T23:31:16.000Z","date":"2024-08-09","kind":"sale","planned":true,"acquired":false,"shares":21766,"price":30.02,"value":653415.32,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F2","text":"These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 17, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.00 to $30.25 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 5,454 shares of Series A Common Stock and (ii) 254,959 unvested restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":260413,"source":{"system":"sec-edgar","filing":"0001991399-24-000004","document":"wk-form4_1723246270.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000004/wk-form4_1723246270.xml","form_type":"4"}},{"id":1437061,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-08-09T23:31:16.000Z","date":"2024-08-09","kind":"exercise","planned":true,"acquired":true,"shares":16218,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into shares of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":282179,"source":{"system":"sec-edgar","filing":"0001991399-24-000004","document":"wk-form4_1723246270.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000004/wk-form4_1723246270.xml","form_type":"4"}},{"id":1511929,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-05-17T20:26:45.000Z","date":"2024-05-15","kind":"exercise","planned":false,"acquired":false,"shares":16666,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock,  and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,666 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 25,788 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock,  and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock,  and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 141,986 shares of Series B Common Stock and (ii) 163,267 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":305253,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16666},"source":{"system":"sec-edgar","filing":"0001991399-24-000002","document":"wk-form4_1715977576.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000002/wk-form4_1715977576.xml","form_type":"4"}},{"id":1511928,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-05-17T20:26:45.000Z","date":"2024-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":25788,"price":24.8,"value":639542.4,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,666 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 25,788 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 11,002 shares of Series A Common Stock and (ii) 254,959 unvested RSUs awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":265961,"source":{"system":"sec-edgar","filing":"0001991399-24-000002","document":"wk-form4_1715977576.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000002/wk-form4_1715977576.xml","form_type":"4"}},{"id":1511927,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-05-17T20:26:45.000Z","date":"2024-05-15","kind":"exercise","planned":false,"acquired":true,"shares":16666,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,666 shares of the Issuer's Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 25,788 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock,  and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":291749,"source":{"system":"sec-edgar","filing":"0001991399-24-000002","document":"wk-form4_1715977576.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000199139924000002/wk-form4_1715977576.xml","form_type":"4"}},{"id":1540204,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-04-17T20:21:59.000Z","date":"2024-04-15","kind":"grant","planned":false,"acquired":true,"shares":107956,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units (\"RSUs\") awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of the Issuer's Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), upon vesting and settlement. The RSUs vest as follows: (i) 50% of the RSUs will vest in eight equal quarterly installments, with the first such installment vesting on May 15, 2024, and (ii) thereafter the remaining 50% of the RSUs will vest in four equal quarterly installments, subject to the Reporting Person's continued service on each such vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Consists of (i) 2,127 shares of Series A Common Stock and (ii) 272,956 unvested RSUs awarded under the Issuer's 2023 Stock Incentive Plan."}],"balance_after":275083,"source":{"system":"sec-edgar","filing":"0001835830-24-000035","document":"wk-form4_1713385310.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000035/wk-form4_1713385310.xml","form_type":"4"}},{"id":1545932,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-04-08T23:15:48.000Z","date":"2024-04-05","kind":"sale","planned":true,"acquired":false,"shares":3545,"price":24.15,"value":85611.75,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on November 17, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.95 to $24.33. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 2,127 shares of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and (ii) 165,000 unvested restricted stock units  awarded under the Issuer's 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":167127,"source":{"system":"sec-edgar","filing":"0001835830-24-000030","document":"wk-form4_1712618133.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000030/wk-form4_1712618133.xml","form_type":"4"}},{"id":1550471,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-04-03T22:17:37.000Z","date":"2024-04-02","kind":"exercise","planned":true,"acquired":false,"shares":23216,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F5","text":"Consists of (i) 125,768 shares of Series B Common Stock and (ii) 196,151 unvested RSUs awarded under the 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":321919,"derivative":{"underlying":"Series A Common Stock","underlying_shares":23216},"source":{"system":"sec-edgar","filing":"0001835830-24-000028","document":"wk-form4_1712182640.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000028/wk-form4_1712182640.xml","form_type":"4"}},{"id":1550470,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-04-03T22:17:37.000Z","date":"2024-04-02","kind":"sale","planned":true,"acquired":false,"shares":28613,"price":24.94,"value":713608.22,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F2","text":"These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on November 17, 2023."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.45 to $25.18. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 5,672 shares of Series A Common Stock and (ii) 165,000 unvested restricted stock units (\"RSUs\") awarded under the 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":170672,"source":{"system":"sec-edgar","filing":"0001835830-24-000028","document":"wk-form4_1712182640.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000028/wk-form4_1712182640.xml","form_type":"4"}},{"id":1550469,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-04-03T22:17:37.000Z","date":"2024-04-02","kind":"exercise","planned":true,"acquired":true,"shares":23216,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"Each share of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), is convertible at any time at the option of the holder into one share of Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":199285,"source":{"system":"sec-edgar","filing":"0001835830-24-000028","document":"wk-form4_1712182640.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000028/wk-form4_1712182640.xml","form_type":"4"}},{"id":1634386,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-02-21T02:27:01.000Z","date":"2024-02-15","kind":"exercise","planned":false,"acquired":false,"shares":16667,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,667 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 22,520 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (i) 148,984 shares of Series B Common Stock and (ii) 196,151 unvested RSUs awarded under the 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":345135,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16667},"source":{"system":"sec-edgar","filing":"0001835830-24-000012","document":"wk-form4a_1708482403.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000012/wk-form4a_1708482403.xml","form_type":"4/A","original_submission_date":"2024-02-16"}},{"id":1634385,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-02-21T02:27:01.000Z","date":"2024-02-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":22520,"price":29.71,"value":669069.2,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,667 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 22,520 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 11,069 shares of Series A Common Stock and (ii) 165,000 unvested RSUs awarded under the 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":176069,"source":{"system":"sec-edgar","filing":"0001835830-24-000012","document":"wk-form4a_1708482403.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000012/wk-form4a_1708482403.xml","form_type":"4/A","original_submission_date":"2024-02-16"}},{"id":1634384,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-02-21T02:27:01.000Z","date":"2024-02-15","kind":"exercise","planned":false,"acquired":true,"shares":16667,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,667 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 22,520 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":198589,"source":{"system":"sec-edgar","filing":"0001835830-24-000012","document":"wk-form4a_1708482403.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000012/wk-form4a_1708482403.xml","form_type":"4/A","original_submission_date":"2024-02-16"}},{"id":1638675,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2024-02-16T21:49:10.000Z","date":"2024-02-15","kind":"exercise","planned":false,"acquired":false,"shares":13305,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 13,305 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 17,470 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Amount consists of (a) 152,346 shares of Series B Common Stock and (b) 196,151\n unvested RSUs awarded under the 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":348497,"derivative":{"underlying":"Series A Common Stock","underlying_shares":13305},"source":{"system":"sec-edgar","filing":"0001835830-24-000006","document":"wk-form4_1708120138.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000006/wk-form4_1708120138.xml","form_type":"4"}},{"id":1638674,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-02-16T21:49:10.000Z","date":"2024-02-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":17470,"price":29.71,"value":519033.7,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 13,305 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 17,470 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 12,757 shares of Series A Common Stock and (ii) 165,000 unvested RSUs awarded under the 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":177757,"source":{"system":"sec-edgar","filing":"0001835830-24-000006","document":"wk-form4_1708120138.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000006/wk-form4_1708120138.xml","form_type":"4"}},{"id":1638673,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2024-02-16T21:49:10.000Z","date":"2024-02-15","kind":"exercise","planned":false,"acquired":true,"shares":13305,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 13,305 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 17,470 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":195227,"source":{"system":"sec-edgar","filing":"0001835830-24-000006","document":"wk-form4_1708120138.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583024000006/wk-form4_1708120138.xml","form_type":"4"}},{"id":1737269,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series B Common Stock","published_at":"2023-11-17T22:03:06.000Z","date":"2023-11-15","kind":"exercise","planned":false,"acquired":false,"shares":16305,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Consists of (a) 132,768 shares of Series B Common Stock and (b) 229,034 unvested RSUs awarded under the 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement."}],"balance_after":361802,"derivative":{"underlying":"Series A Common Stock","underlying_shares":16305},"source":{"system":"sec-edgar","filing":"0001835830-23-000012","document":"wk-form4_1700258568.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583023000012/wk-form4_1700258568.xml","form_type":"4"}},{"id":1737268,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2023-11-17T22:03:06.000Z","date":"2023-11-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":21883,"price":28.7,"value":628042.1,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,305 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 21,883 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Consists of (i) 5,672 shares of Series A Common Stock and (ii) 176,250 unvested RSUs awarded under the 2023 Stock Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement."}],"balance_after":181922,"source":{"system":"sec-edgar","filing":"0001835830-23-000012","document":"wk-form4_1700258568.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583023000012/wk-form4_1700258568.xml","form_type":"4"}},{"id":1737267,"issuer":{"id":3775,"kind":"organization","name":"Klaviyo, Inc.","symbol":"KVYO"},"owners":[{"id":18020,"kind":"person","name":"Edmond Landon","position":1,"cik":"0001991399","reported_name":"Edmond Landon","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Series A Common Stock","published_at":"2023-11-17T22:03:06.000Z","date":"2023-11-15","kind":"exercise","planned":false,"acquired":true,"shares":16305,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Represents 16,305 shares of Series B Common Stock, par value $0.001 per share (\"Series B Common Stock\"), automatically converted into Series A Common Stock, par value $0.001 per share (\"Series A Common Stock\"), and 21,883 shares of Series A Common Stock subsequently withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units (\"RSUs\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of Series A Common Stock of the Issuer, and will automatically convert into Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date."}],"balance_after":203805,"source":{"system":"sec-edgar","filing":"0001835830-23-000012","document":"wk-form4_1700258568.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1991399/000183583023000012/wk-form4_1700258568.xml","form_type":"4"}}]}