Mozilla has officially announced the end of Firefox support for 32-bit Linux systems, setting September 2026 as the final cutoff. The decision comes after years of maintaining builds for older hardware, long after most browsers and operating systems had already moved on.
According to Mozilla engineers Julien Cristau and Sylvestre Ledru, Firefox 144 will be the last regular release to include 32-bit Linux builds. Starting with Firefox 145, scheduled for 2026, users on those systems won’t get new versions.
The company explained that maintaining the 32-bit branch has become increasingly difficult and unreliable, as most Linux distributions have already dropped 32-bit support.
And I am inclined to agree with that. It’s true that mainstream Linux distros have largely phased out 32-bit as a primary architecture, and modern CPUs have been exclusively 64-bit for nearly two decades.
But let’s not also forget that, for example, Debian still ships i386 builds (though they are community-maintained, not first-class), Slackware continues to support 32-bit, plus some smaller distros (e.g., antiX, Devuan, Puppy, Bodhi Legacy) intentionally keep 32-bit alive for old hardware.
So, for people who can’t immediately switch to 64-bit, there’s still some breathing room. Firefox ESR 140 will continue to ship 32-bit builds and get security updates until at least September 2026.
After that, though, there won’t be an officially supported option. Mozilla is strongly recommending users migrate to a 64-bit operating system and install the 64-bit version of Firefox to stay current and secure.
This marks the end of a long run where Firefox kept supporting older machines in the name of reducing unnecessary obsolescence. But with most of the Linux world having already moved to 64-bit, Mozilla says the shift is about focusing its resources on delivering the best experience for modern systems.
