144 0001856597 XXXXXXXX LIVE 0001496963 Squarespace, Inc. 001-40393 225 Varick Street 12th Floor New York NY 10014 1-646-580-3456 Anthony Casalena Officer Class A Common Stock Goldman Sachs & Co. LLC 200 West Street New York NY 10282 92511 4304536.83 90630649 10/14/2024 NYSE Class A Common Stock 08/18/2017 Acquired as compensation -- Restricted Stock Awards The Issuer N 92511 08/18/2017 Compensation N ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/04/2024 38466 1740963.47 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 07/29/2024 62011 2727746.07 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 08/09/2024 47787 2109547.56 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/11/2024 143500 6657424.2 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/30/2024 38900 1805590.18 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 08/08/2024 68659 3033347.75 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/01/2024 106500 4941259.2 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 08/22/2024 52485 2351574.68 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/18/2024 47466 2200348.14 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 07/16/2024 10154 444589.84 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/11/2024 6500 300798.55 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 07/15/2024 59882 2621831.57 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 08/21/2024 23726 1061408.71 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/18/2024 32977 1529931.64 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/05/2024 33375 1507255.05 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/17/2024 145182 6726398.21 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 07/16/2024 72734 3186956.58 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 07/26/2024 63756 2804722.07 The sales of shares set forth herein are made in connection with a selling plan dated 3/5/2024, that is intended to comply with Rule 10b5-1(c). All shares to be sold by the Anthony Casalena Revocable Trust. Filing intended to be made on 10/14/2024. Unable to be submitted due to federal holiday. 10/15/2024 03/05/2024 Goldman Sachs & Co. LLC on behalf of Anthony Casalena