How do I tell if I have the 32-bit or 64-bit Firefox?

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  • Revision id: 127819
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  • Creator: Chris Ilias
  • Comment: removed section about user-agent, and made programs list section into step-by-step instructions. https://support.mozilla.org/kb/how-do-i-tell-if-32-bit-or-64-bit/discuss/6674
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  • Reviewed by: AliceWyman
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This article only applies to Firefox on Windows.

Both 32-bit and 64-bit versions of Firefox are available for 64-bit versions of Windows 7 and above. Not sure whether you're running 32-bit or 64-bit Firefox? This article explains how to find out.

  1. Open the Windows Start menu and click on SettingsControl Panel. Open the SystemPrograms panel, then select the Apps & features tabPrograms and Features panel.
  2. Scroll down the list of appsprograms until you find the Mozilla Firefox item.
    Win7Programs
    • If it contains x64, you're running the 64-bit version of Firefox.
    • If it contains x86, you're running the 32-bit version of Firefox. Want to switch? For instructions, visit How to switch from 32-bit to 64-bit Firefox.
    • If both are listed, it's because the 64-bit version does not remove the 32-bit version. They are separate. You can remove the 32-bit version if you want. Removing one will not affect the other, and you won't lose your data.