X0609 4 2026-08-20 0 0001462056 Backblaze, Inc. BLZE 0001857850 Budman Gleb false 2261 MARKET STREET STE 81006 SAN FRANCISCO CA 94114 1 1 0 0 CEO and Chairperson 0 Class A Common Stock 2026-08-20 2026-08-20 4 D 0 11083 16.24 D 2204958 D Class A Common Stock 2026-08-21 2026-08-21 4 S 0 12855 15.82 D 2192103 D Represents previously issued restricted stock units that the Issuer retired for cash upon vesting in lieu of issuing shares of common stock. These restricted stock units were settled by the Issuer at the closing price per share of the Issuer's common stock on the vesting date. The sales reported on this Form 4 represent shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units. These sales are mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and do not represent discretionary trades by the Reporting Person. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.82 to $15.83, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth herein. /s/ Evangeline Cheung, Attorney-in-Fact 2026-08-24