Mozilla has reached the point of terminating Firefox support for outdated operating systems, marking the end of compatibility with Windows 7 nearly 15 years after its debut in 2009. Beginning with release 115, the browser will cease functioning on Windows 7, 8, and 8.1, signaling a definitive close to an extended era of accommodation for legacy setups.
Although version 115 has become obsolete— with the current stable edition at 147— it remains available through the Extended Support Release track. This variant prioritizes stability by delivering infrequent major updates, roughly annually, while focusing on critical security fixes. Tailored for business environments requiring reliability or for users with aging systems, the ESR build for version 115 will receive maintenance until late February 2026.
Mozilla's commitment to these legacy Windows editions has outlasted expectations. The company originally planned to withdraw support in 2024 but delayed the cutoff on two occasions. While reports from sources like Neowin hinted at possible further prolongations with tentative timelines, Mozilla has now confirmed a firm conclusion without additional extensions.
In contrast, major competitors such as Chrome and Edge discontinued official backing for Windows 7 years earlier, leaving Firefox as one of the last holdouts.
For those reluctant to abandon older Windows installations, Mozilla recommends migrating to Windows 10 or 11— though the former faces its own impending end-of-support challenges— or adopting Linux distributions, many of which feature Firefox as the standard browser.