How to switch from 32-bit to 64-bit Firefox

This article is no longer maintained, so its content might be out of date.

This article only applies to Firefox on Windows.

Note: Mozilla began to automatically switch users from 32-bit Firefox to 64-bit Firefox, starting with the update to Firefox version 56.0.1 on October 9, 2017. See How do I tell if I have the 32-bit or 64-bit Firefox? to find out if you already have 64-bit Firefox. To learn more, see this Mozilla blog post and this Mozilla Wiki.

The 64-bit version of Firefox can provide better performance than the 32-bit version. 64-bit Firefox requires a 64-bit version of Windows 7 or higher. To see if you have a 64-bit Windows version visit this Microsoft help page.

When you switch to the 64-bit version of Firefox, your Firefox user data (passwords, bookmarks, settings, add-ons, etc.) will not be removed.

Warning: Firefox creates dedicated profiles for each installation. See Recover user data missing after Firefox update if the new 64-bit installation of Firefox results in missing profile data. You may wish to uninstall your 32-bit Firefox version before installing 64-bit Firefox.

Follow these steps to switch from 32-bit to 64-bit Firefox:

  1. Go to this Mozilla Firefox download page and select the Windows 64-bit installer.
  2. Download the Firefox Setup file and save it to your computer.
    • Do not run the installer yet.
  3. Close Firefox. Click the Firefox menu Fx89menuButton and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu Fx89menuButton and select Quit.
  4. Remove the 32-bit version of Firefox. Open the Windows Start menu and click on SettingsControl Panel. Open the SystemPrograms panel, then select the Apps & features tabPrograms and Features panel.
  5. Scroll down the list of appsprograms until you find the Mozilla Firefox item that contains x86 in the name. Select it, and click Uninstall.
  6. Follow the prompts in the Uninstall Wizard to complete the removal of the 32-bit version.
  7. Run the Firefox Setup file you saved to your computer and follow the prompts to install the 64-bit version of Firefox.

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