X0609 4 2026-11-02 0 0001562088 Duolingo, Inc. DUOL 0001229590 GORDON WILLIAM B false C/O DUOLINGO, INC. 141 S ST CLAIR STREET, SUITE 501 PITTSBURGH PA 15206 1 0 0 0 1 Class A Common Stock 2026-11-02 4 S 0 300 132.1364 D 68115 D Class A Common Stock 2026-11-02 4 S 0 300 133.30 D 67815 D Class A Common Stock 2026-11-02 4 S 0 300 134.5067 D 67515 D Class A Common Stock 2026-11-02 4 S 0 3941 135.5342 D 63574 D Class A Common Stock 2026-11-02 4 S 0 1759 136.2531 D 61815 D Class A Common Stock 2026-11-02 4 S 0 1326 137.5951 D 60489 D Class A Common Stock 2026-11-02 4 S 0 1374 138.4004 D 59115 D Class A Common Stock 2026-11-02 4 S 0 700 139.1992 D 58415 D The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 9, 2026. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $131.68 to $132.35, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $132.93 to $133.86, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $133.95 to $134.80, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $134.99 to $135.97, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $135.99 to $136.97, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $137.00 to $137.87, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $138.03 to $138.94, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $139.09 to $139.54, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. /s/ Stephen Chen, as Attorney-in-Fact for William B. Gordon 2026-11-04