Mozilla is ending Firefox support for 32-bit Linux in October 2025, citing reliability challenges and shifting focus to modern builds, a defining moment for open source browsing.
Mozilla has announced it will end support for 32-bit Linux builds of Firefox, closing a chapter that began with the browser’s Linux debut in 2004. The final supported release, Firefox 144, is scheduled for 14 October 2025. Firefox 145 will be the first version to drop 32-bit Linux support.
Explaining the decision, Mozilla stated: “Maintaining Firefox on this platform has become increasingly difficult and unreliable.” The organisation added that it will now focus engineering efforts on “delivering the best and most modern Firefox.” The move reflects the declining use of 32-bit Linux distributions in recent years.
Mozilla’s decision stands out in context. Google Chrome discontinued 32-bit Linux support in 2016, while Ubuntu dropped it in 2017. By contrast, Mozilla continued support far longer in order to help “users extend the life of their hardware and reduce unnecessary obsolescence.”
For users still running 32-bit Linux systems, immediate disruption is limited. Firefox 144 will remain usable, though it will not receive future features or security patches. Firefox ESR 140 will continue to receive security updates until September 2026. For long-term reliability, migration to 64-bit hardware and distributions is recommended.
The end of 32-bit Linux support signals more than just a technical shift. It marks the conclusion of an era where open source developers resisted obsolescence in the interest of inclusivity and hardware longevity. With Firefox stepping away, the last major open source browser to support 32-bit Linux is gone, underscoring the ecosystem’s definitive transition to 64-bit.
However, thanks to Firefox’s open source foundations, community-driven forks could continue 32-bit builds for legacy hardware users, keeping the tradition alive beyond Mozilla’s official withdrawal.
