X0607 3 2026-03-26 0 0001842731 SIMILARWEB LTD. SMWB 0001969639 Seror Benjamin true C/O 33 YITZHAK RABIN RD. GIVATAYIM L3 1 0 0 0 Ordinary Shares 316250 D Restricted Share Units, each representing one Ordinary Share 18750 D Restricted Share Units, each representing one Ordinary Share 40000 D Restricted Share Units, each representing one Ordinary Share 60000 D Restricted Share Units, each representing one Ordinary Share 80000 D Options to purchase one Ordinary Share 2.38 2021-11-09 2030-11-08 Ordinary shares, par value NIS 0.01 per share 18750 D Options to purchase one Ordinary Share 3.04 2021-01-29 2031-01-28 Ordinary shares, par value NIS 0.01 per share 231250 D The Reporting Person was granted restricted stock units ("RSUs"), which each represent a contingent right to receive one ordinary share of Similarweb Ltd (the "Company"). The RSUs vest in 25% after one year period & 12 equal installments every quarter afterwards with the first vesting date on 02/15/2024, subject to the Reporting Person's continued service to the Company or its subsidiaries through each vesting date. The Reporting Person was granted restricted stock units ("RSUs"), which each represent a contingent right to receive one ordinary share of Similarweb Ltd (the "Company"). The RSUs vest in 25% after one year period & 12 equal installments every quarter afterwards with the first vesting date on 02/15/2025, subject to the Reporting Person's continued service to the Company or its subsidiaries through each vesting date. The Reporting Person was granted restricted stock units ("RSUs"), which each represent a contingent right to receive one ordinary share of Similarweb Ltd (the "Company"). The RSUs vest in 25% after one year period & 12 equal installments every quarter afterwards with the first vesting date on 02/15/2026, subject to the Reporting Person's continued service to the Company or its subsidiaries through each vesting date. The Reporting Person was granted restricted stock units ("RSUs"), which each represent a contingent right to receive one ordinary share of Similarweb Ltd (the "Company"). The RSUs vest in 25% after one year period & 12 equal installments every quarter afterwards with the first vesting date on 02/15/2027, subject to the Reporting Person's continued service to the Company or its subsidiaries through each vesting date. The Options are fully vested & immediately exercisable. This Form 3 has been filed after March 18,2026 but prior to April 20,2026 in reliance on the temporary relief made available to the directors and officers of certain foreign private issuers by the Staff of the Securities and Exchange Commission in its no action letter dated March 13,2026. Benjamin Seror by: Oppenheimer Israel, as Attorney-in-fact 2026-03-26