Mozilla had planned the 64-bit version of Firefox almost a decade ago when the 64-bit programming first gained popularity. But the project kept getting delayed for so many years because of more than one reasons. At one point, Mozilla even announced that they are giving up the 64-bit version project. But eventually they managed to release the 64-bit version of Firefox browser for Windows last December. Now if you are running a 64-bit version of Windows and you download Firefox from the Mozilla web site, you would most probably get the 64-bit version of Firefox. But if you download it from third party sites, then perhaps you would end up with a 32-bit version copy of Firefox.
Here is a simple way of knowing whether you are running a 32-bit version of Firefox or the 64-bit version of Firefox:
- Launch Firefox browser, type about:buildconfig in the address bar and press Enter.
- The information displayed will be about the configuration settings of compiling the Firefox browser. If you see x86_64-pc-mingw32 under the target field of build platform then you have a 64-bit version of Mozilla Firefox browser.
- However, if the target field reads i686-pc-mingw32 then you are running a 32-bit version of Firefox browser.
Another quick way to know if you have a 64-bit version or 32-bit version of Firefox, is to use the Windows Task Manager. You can launch the Task Manager using the hotkey Ctrl+Shift+Esc and if it lists Firefox process as just Firefox, then you have 64-bit version of Firefox. However, if you see Firefox (32-bit) in the Task Manager, then obviously you have 32-bit version of Firefox.
As you can see in the screenshot above, you can run two different versions of Firefox simultaneously without much impact on the Windows system. The old method of running two or more different versions of Firefox at the same time still applies even in the case of 32-bit or 64-bit versions of Firefox.