Mozilla has once again decided to extend the life of Firefox on aging versions of Microsoft’s operating system, giving users more time before they’re forced to upgrade. Earlier this year, the company had promised support until mid-August 2025, but its updated release calendar now confirms that security updates for Firefox on Windows 7, Windows 8, and Windows 8.1 will continue until at least March 24, 2026. For those counting, that’s another six-month reprieve.
At present, running Firefox on these older systems requires using the Firefox Extended Support Release (Old ESR) branch, which is currently on version 115. Mozilla says that the Old ESR channel will continue to be maintained, with plans to transition it to version 140 in July 2026. This ensures that users of unsupported operating systems still receive security patches, even if they miss out on some of the more cutting-edge features of Firefox’s mainline builds.
That said, this extension isn’t a permanent solution. Mozilla has already signaled that it will reassess the situation in February 2026, at which point it will announce whether Firefox support for these legacy Windows systems will carry on or finally come to an end. Given that Microsoft officially ended updates for Windows 7 back in January 2020 and Windows 8.1 in January 2023, Mozilla’s continued commitment to patching Firefox is a rare lifeline for users who can’t or won’t move to a newer OS.
