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 67352 1931655.36 88124267 12/15/2023 NYSE Class A Common Stock 08/18/2017 Acquired as compensation -- Restricted Stock Awards The Issuer N 67352 08/18/2017 Compensation N ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/17/2023 19780 596624.14 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/18/2023 21193 631608.62 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/04/2023 21679 619475.26 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/21/2023 11189 313561.65 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/05/2023 26705 767515.05 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 09/22/2023 71720 2058364 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/30/2023 42013 1190203.08 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 10/31/2023 18630 528901.97 ANTHONY CASALENA REVOCABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 11/10/2023 37429 1080833.49 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 11/13/2023 44735 1279573.1 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 11/24/2023 22172 626720.4 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 11/27/2023 41711 1171140.6 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 12/04/2023 45029 1285888.65 ANTHONY CASALENA REVOCVABLE TRUST 225 Varick Street 12th Floor New York NY 10014 Class A Common Stock 12/05/2023 45435 1283111.66 The sales of shares set forth herein are made in connection with a selling plan dated 8/11/2023, that is intended to comply with Rule 10b5-1(c). All shares to be sold by the Anthony Casalena Revocable Trust. 12/15/2023 08/11/2023 Goldman Sachs & Co. LLC on behalf of Anthony Casalena