Firstly, Mozilla doesn't develop or maintain the portable version(s) of Firefox. Those are modified versions of Firefox that are released by independent developers.

It's possible that the developers did at one point distinguish between the 32-bit and 64-bit versions of Firefox and now maybe they don't anymore.

I've also noticed that most of the websites that offer the portable version are just taking the version from PortableApps.com. Since there is only one version on that website, that could also be the reason that they happen to both be 64-bit.

The PortableApps package has both versions, but it will self-select which to run. If you have a 64-bit system...

If you if you look in your downloaded FFxxxx.paf.exe with an archive manager, you can see both folder trees. I would assume both "installations" should be in the self-extracted portable package.

crankygoat said

The PortableApps package has both versions, but it will self-select which to run. If you have a 64-bit system... If you if you look in your downloaded FFxxxx.paf.exe with an archive manager, you can see both folder trees. I would assume both "installations" should be in the self-extracted portable package.

That's exactly what I would have thought but it didn't happen. I was running 32bit for months and didn't even realize it. Not sure if I would have noticed the difference...in what area would it matter? Websites with high res videos maybe? I'm using Win7 on a i5 3ghz system with 16gb DDR3 ram. I do notice some audio distortion sometimes playing videos but its rare and I can't replicate it when I play that part again. I use Process Explorer and it never seems to be stressed.

Note that in current Firefox releases the user agent always shows the platform version, i.e. a 32 bit Firefox version on a 64-bit platform still shows Win64 in the user agent.

There isn't a difference you would notice. All 64-bit means is that Firefox natively uses the 64-bit addressing in a 64-bit OS for 64-bit processor architecture.

In fact, there are circumstances under which it has been suggested to use the 32-bit version, to remediate issues someone was having with a 64-bit version. I don't know if that is any longer true, or maybe just for older systems.

Regardless, while Firefox cannot control what PortableApps decides to run on your system, here is what PortableApps has to say: https://portableapps.com/manuals/PortableApps.comLauncher/topics/64-bit.html Reading further, it seems the general philosophy is to never run a 64-bit version unless there are very significant reasons to do so. https://portableapps.com/manuals/PortableApps.comLauncher/ref/launcher.ini/launch.html#std:ini-key-[Launch]:ProgramExecutable64

(Note that FirefoxPortable.exe is not the browser, it is a launcher and wrapper made to fool Firefox into using the portable directory structure. This is how all all non-portable applications are handled to make them portable.)