Firefox to end support for 32-bit Linux in 2026

Mozilla has announced that it will end support for Firefox on 32-bit Linux systems in 2026. This shouldn't affect most users, but still it's something worth mentioning.

It may seem surprising that Mozilla has supported 32-bit Linux for so long, and indeed it has. For reference, Google Chrome ended support for 32-bit Linux in 2016. So in 2026, Mozilla will have supported 32-bit Linux for ten years longer than Chrome did. That's pretty cool.

How many people still use Linux 32 bit? I can't find the exact statistics about it, but I took a look at the Firefox Public Data Report's Hardware section. It appears that, as of August 2025, 86.761% of Firefox users are on 64-bit computers. 4.550% of users have a 64-bit ARM computer, I'm assuming that includes Apple Silicon Macs, and Snapdragon computers. Only 8.689% of Firefox users have a 32-bit computer. It's unclear how many Linux 32-bit users this translates to.

Mozilla's announcement says 32-bit Linux is not supported by many Linux distros, and that maintaining a version of Firefox for the platform has become harder. Most Linux distros like Ubuntu, Mint, Fedora require a 64-bit processor. Linux Mint Debian Edition (LMDE) still supports 32-bit systems. Debian 13 lets you run 32-bit apps, but the distro itself has dropped support for the i386 architecture. Debian 12 is still supported, LTS ends on June 30, 2028. I'm sure there are other distros that support 32-bit, but it's becoming rarer.

Firefox 144 will be the last version to support 32-bit Linux, it's not far away. According to Mozilla's release calendar, Firefox 144 will be released on October 14, 2025. Hey, that's when Windows 10 reaches end of life too. Firefox 145 and above will be 64-bit only. If you are using a 32-bit Linux machine, don't worry just yet. Mozilla says it will continue to support 32-bit Linux in Firefox ESR 140 builds so you can stay on that version until September 2026 to continue receiving security updates.

Support for Firefox ESR 115 has been extended several times to support Windows 7, 8, 8.1, macOS 10.12 to 10.14, so there is a chance that Mozilla may extend the same courtesy for 32-bit Linux users as well.

I can't say I've seen a 32-bit computer since maybe a netbook or two in 2010 or earlier. Looking at the Wikipedia entries for Intel and AMD processors show that both processor manufacturers stopped making 32-bit only CPUs nearly 20 years ago. Unless your computer has a processor that's from the early 2000s or older, you don't have to be worried. That is, unless you are using Linux 32-bit on a system that supports 64-bit for some reason, in which case you just need to switch to a 64-bit version of the distro.

Mozilla is encouraging 32-bit users to move to a 64-bit operating system, to continue using future versions of Firefox.

Are you still using a 32-bit OS?

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Posted Thursday 11 September 2025 at 2:01 am AEST (my time).

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