X0609 4 2026-08-31 0 0001517413 Fastly, Inc. FSLY 0001189229 PAISLEY CHRISTOPHER B false C/O FASTLY, INC. 475 BRANNAN STREET, SUITE 300 SAN FRANCISCO CA 94107 1 0 0 0 1 Class A Common Stock 2026-08-31 4 S 0 3000 23 D 280485 I See Footnote Class A Common Stock 15828 D The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 26, 2026. Amounts reflect the shift from indirect to direct ownership of 1,000 shares to correct an administrative error in the reporting person's Form 4 filed on June 2, 2026, which was carried over on the reporting person's Form 4 filed on June 5, 2026. The June 2, 2026 filing inadvertently reported that the sale of 1,000 shares was deducted from the reporting person directly, rather than the Christopher Paisley TTEE Paisley Living Trust DTD 12/28/94. Total beneficial ownership was correctly reported on both prior filings. The shares are held by the Christopher Paisley TTEE Paisley Living Trust DTD 12/28/94. /s/ Tara Seracka, Attorney-in-Fact 2026-09-02