If you’re still clinging to an older version of Windows, Mozilla has some good news for you: Firefox will keep receiving security updates on Windows 7, Windows 8, and Windows 8.1 until March 24, 2026. The company had previously marked August 2025 as the cutoff, but its newly revised release calendar shows yet another extension—offering users of legacy systems an additional six months of breathing room.
To keep using Firefox on these older platforms, users must run the Firefox Old ESR (Extended Support Release) branch. Currently at version 115, the ESR branch delivers stability and long-term security fixes rather than frequent new features. According to Mozilla’s roadmap, the ESR branch is scheduled to roll over to version 140 in July 2026, further demonstrating the company’s willingness to support those who have yet to upgrade to Windows 10 or 11.
Of course, this extension won’t last forever. Mozilla has stated that it will review the support policy in February 2026, and at that time, a final decision will be made on whether to continue support or officially end it. Until then, users of outdated Windows versions can take comfort in the fact that at least one major browser still provides them with essential security updates. In an ecosystem where Microsoft and most third-party developers have long since moved on, Firefox’s extended support feels like a rare gesture of goodwill toward those holding onto legacy hardware and software.