X0609 4 2026-09-11 0001032975 LOGITECH INTERNATIONAL S.A. LOGI 0001475223 Harnett Samantha false C/O LOGITECH INC. 3930 NORTH FIRST STREET SAN JOSE CA 95134 false true false false CHIEF LEGAL OFFICER 1 Registered Shares 2026-09-11 4 S 0 4051 99.9623 D 49311 D Registered Shares 2026-09-11 4 S 0 5830 101.2206 D 43481 D Registered Shares 2026-09-11 4 S 0 5884 102.31 D 37597 D Registered Shares 2026-09-11 4 S 0 500 102.787 D 37097 D The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 12, 2026. Reflects weighted average sale price. Actual sale prices ranged from $99.73 to $100.69. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects weighted average sale price. Actual sale prices ranged from $100.74 to $101.72. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects weighted average sale price. Actual sale prices ranged from $101.75 to $102.70. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects weighted average sale price. Actual sale prices ranged from $102.755 to $102.805. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. /s/ Nathalie Hoegger as attorney in fact for Samantha Harnett 2026-09-14