Only 1.7% of all Firefox users on Windows ran a 64-bit version of the browser in 2016 while the majority of users ran a 32-bit version of Firefox according to Mozilla. One core reason for that was that Mozilla pushed the 32-bit version of Firefox on the main download page and not the 64-bit version.
Firefox users who wanted to download and use a 64-bit version of the browser on Windows needed to search for it actively. That was the main reason why only 1.7% ran a 64-bit version of Firefox at the time.
The situation has changed significantly in recent time. Mozilla released a 64-bit version of the Firefox web browser for Windows last year and started to promote it more actively in recent time.
The main Firefox Stable download page on the Mozilla website offers 32-bit and 64-bit versions of the browser with 64-bit the default nowadays.
32-bit versions of Firefox run on 32-bit and 64-bit versions of Windows. 64-bit versions on the other hand only on 64-bit Windows versions.
Mozilla revealed recently that more than 30% of Firefox installations are on 32-bit versions of Windows.
You have a couple of options to find out if you are running a 32-bit or 64-bit version of Firefox. If you have not modified the user agent of the browser, you may load about:support in the browser's address bar and check the user agent string.
If it includes Win64 and/or x64 it is a 64-bit version. Please note that Wow64 is displayed if you run a 32-bit version of Firefox on a 64-bit system.
You may check the Windows Task Manager instead if you prefer that. Windows display (32 bit) next to 32-bit processes so that you know right away when you open it using Ctrl-Shift-Esc.
Before we take a look at how to upgrade from a 32-bit version of Firefox to a 64-bit version, it is important to understand why upgrading makes sense (or not).
Firefox 32-bit and 64-bit offer the same browsing functionality for the most part. 64-bit versions were limited when it came to support for plugins -- only Flash and Silverlight are supported. If you depend on other plugins, say Java or Unity, you could not upgrade in the past; this changed with Mozilla's decision to end support for NPAPI plugins in the Firefox browser.
Firefox users could run 32-bit and 64-bit versions of Firefox side by side on the system to overcome the limitation in the past but since NPAPI support is not really an option anymore, plugin support is no longer part of the equation when it comes to selecting between 32-bit and 64-bit versions of the Firefox browser.
The main benefit of running a 64-bit application is that it is not limited to using 4 GiB of memory. If you have more than 4 GiB of physical memory installed, Firefox may benefit from the extra RAM especially if you throw lots of tabs at it.
This is not the case if you just run a tab or two in the browser, but if you run dozens or hundreds, lots of extensions, or run memory hungry apps, then you will benefit from the extra memory surely.
Mozilla started to migrate eligible 32-bit copies of Firefox on Windows to 64-bit copies automatically when Firefox 56 was released in mid 2017.
Good news is that the upgrading is as easy as installing Firefox anew on the operating system. I suggest you back up profile data using MozBackup or Febe, or a comparable solution. This enables you to go back should things go wrong during the process.
Next step is to download the 64-bit version of Firefox that you plan on using.
Firefox 64-bit Downloads
To upgrade, simply run the installer and follow the instructions. You may run the newly installed 64-bit version of Firefox and it will pick up the default user profile automatically.
You may downgrade to 32-bit at any time in the future by following the instructions again. Just make sure you download a 32-bit copy of Firefox that time as you need to install it.
Please note that you will end up with two copies of Firefox installed on your system. A 32-bit version and a 64-bit version. Once you have made sure that the 64-bit version works, you may remove the 32-bit version of Firefox from the system.Advertisement
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Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.