All good things come to an end, and so do a few “wait, that’s still going?” things: Mozilla has announced it is ending support for 32-bit Linux in October.

Now, if you’re reading this from a 32-bit Linux distro (which I hope isn’t the one this blog is about, as Ubuntu dropped 32-bit support back in 2017) you needn’t panic unduly — I’ll get to why not in a moment.

Mozilla has been churning out 32-bit builds of Firefox far longer than rival web browsers in an effort to help ‘users extend the life of their hardware and reduce unnecessary obsolescence’. And they no doubt have: Google Chrome discontinued 32-bit Linux builds in 2016.

So why is Mozilla ending support for Firefox on 32-bit Linux distributions now?

Aside from the obvious element (I don’t want to ruin anyone’s day, but 32-bit Linux distributions are not exactly widely used these days), it’s a little more technical: Mozilla say ‘maintaining Firefox on this platform has become increasingly difficult and unreliable’.

To focus their engineering efforts on ‘delivering the best and most modern Firefox’, Mozilla has chosen to end support for 32-bit Linux distributions. The Firefox 144 release (out on 14 October, 2025) will be the final version to officially support 32 bit Linux.

Which means, Firefox 145 will be the first version to not offer 32-bit Linux support since the browser first launched on Linux back in 2004 (while Phoenix 0.1 supported Linux in 2002, Phoenix wasn’t technically Firefox).

A world without 32-bit Firefox

If you’re running running a 32-bit Linux distribution and relying on Firefox for the web-browsing needs, you do not need to panic just yet.

Firstly, Firefox 144 should remain working for a long while yet. It won’t get new features or security patches of course, but it won’t stop working overnight. Over time, websites may start rendering poorly, or require features not present, but that’s down the line.

Secondly, it is possible to switch to Firefox 140 ESR instead. The ESR build receives ongoing support (including security updates) until September 2026. What it lacks in newer bells and whistles it makes up for in, y’know, being supported.

Migrating to 64-bit CPU, with a modern 64-bit Linux distro and installing the 64-bit version of Firefox is an obvious solution to the situation, and for anyone’s main, day-to-day computer, a sensible one.

But for those keeping old computer(s) in service for nerdy nostalgia, hobby projects or some other need, the lack of the latest Firefox won’t be any more of an stickler than the lack of other key software or OS updates.