How to Download an Older Version of Firefox

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Go back to an older version of Firefox on desktop or mobile

Written by Nicole Levine, MFA

Last Updated: February 15, 2026 Fact Checked

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• Downgrading on a Computer
|
• Downgrading on Android
|
• Risks of Downgrading Firefox
|
• Video
|
• Q&A
|
• Warnings

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Mozilla, the organization that develops Firefox, offers downloads of all old versions of the app for Windows, macOS, and Android for testing. While Mozilla doesn't recommend downgrading Firefox for security reasons, there may be times when using an older Firefox version is needed. To learn how to downgrade Firefox on your PC, Mac, or Android phone or tablet, read on!

Quick Steps to Downgrade Firefox on Windows & Mac

1. Go to ftp.mozilla.org/pub/firefox/releases in a web browser.
2. Select the version you want to install.
3. Select your operating system, then your language.
4. Click the download link.
5. Disconnect from the internet.
6. Run the installer.
7. Open Firefox and disable automatic updates in ☰ > Settings.

Steps

Section 1 of 3:

Download an Older Version of Firefox

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1. 1
   Find out which version of Firefox you have now. If you're having trouble with Firefox and want to go back to the version you had before, you'll first need to figure out which version you have now. To find your version:

   • Click the menu ☰ with three horizontal lines at the top-right corner.
   • Click Help.
   • Click About Firefox.
   • The version number appears below "Firefox Browser" in the window (e.g., 86.0 64-bit).
   • Write down the full version number so you don’t forget it.
2. 
   2
   Go to ftp.mozilla.org/pub/firefox/releases in a web browser. This is the FTP link that archives all versions of Firefox you can still install.
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3. 
   3
   Select the Firefox version you want to install.

   • For example, if you want to downgrade to version 129.0.1, you'd click 129.0.1.
   • Versions with a lowercase "b" in the name are beta versions.
4. 
   4
   Click the folder for your operating system and architecture. The folders here don't always have the most straightforward names, so use these tips to help you make the right selection:

   • Mac: This one is actually straightforward—click the folder called mac.
   • Windows: Look for "win32/" (32-bit Windows) or "win64/" (64-bit Windows) in the link text. Make sure you choose the same bit number you saw in your version number.
     • Not sure which version you need? See this guide to finding out your computer's architecture.
5. 
   5
   Click the language folder. The list on this page is abbreviated regional languages.

   • For example, if you speak English and are in the United States, you would click the en-US folder.
6. 
   6
   Click the download link. If you're using Windows, choose the link that ends with ".exe." If you have a Mac, choose the one that ends with ".dmg." This downloads the installer to your computer.

   • Depending on your browser settings, you may be prompted to confirm the download or select a download location before the download begins.
7. 7
   Uninstall the current version of Firefox. Here's how:

   • Windows
     • Press Windows key + S to open the search bar and type add remove.
     • Click Add or remove programs.
     • Scroll down and click ••• on Mozilla Firefox.
     • Click Uninstall and follow the on-screen instructions.
   • Mac
     • Open Finder and click the Applications folder.
     • Drag the Firefox icon to the Trash.
8. 
   8
   Disconnect from the internet. Firefox includes a security feature that installs the latest security updates in the background. To prevent Firefox from automatically updating to the newest version, disconnect from the internet before installing the downgraded version. You can disable Wi-Fi or remove the Ethernet cable from your computer after the installation file is finished downloading.
9. 
   9
   Double-click the Firefox setup file to install Firefox. You will find it in your default Downloads folder. Follow the on-screen instructions to install Firefox. When it's finished installing, it will launch for the first time.

   • On macOS Sierra and later, you may need to manually allow installation before continuing.
10. 
    10
    Create a new profile. As of version 67, Firefox now has downgrade protection, which requires you to create a separate profile from the one you used in the most current version. You just won't be able to use your previous profile in the downgraded version. Click Create New Profile when prompted and follow the on-screen instructions to set up a new profile.

    • Don't worry, you won't lose your bookmarks or other profile info, which will still be available once you upgrade to the latest version.
11. 
    11
    Disable automatic updates as soon as Firefox launches. Firefox is set up to update automatically in the background so you always have the latest security patches. If you want to keep your downgraded version, you will need to turn this feature off. Here's how:

    • Click the three-line menu ☰ at the top-right corner and select Settings.
    • Scroll down to the "Firefox Updates" section.
    • Select Check for updates but let you choose to install them.
    • Remove the checkmark from "Use a background service to install updates."
12. 
    12
    Reconnect to the internet. Now that you've downgraded to an older version and disabled automatic updates, you can use it as long as you like.
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Section 2 of 3:

Downgrading on Android

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1. 1
   Allow installation of unknown apps on your Android. If you don't want the newest version of the Firefox app, you can download older versions as APK files from ftp.mozilla.org/pub/fenix/releases. To install the APK file, you'll first need to allow APK installs. The steps to do this vary by Android model–here's how to do it on a Samsung Galaxy phone or tablet:

   • Open Settings and go to Security and privacy > More security settings.
   • Tap Install Unknown Apps.
   • Toggle on the switch for the web browser you'll be using to download the old version of Firefox.
   • Toggle on the switch for your file manager (e.g., My Files, Files by Google).
2. 2
   Open your browser and go to ftp.mozilla.org/pub/fenix/releases. This FTP link contains many folders, each named after a version of the Android mobile app.

   • If you want much older versions of Firefox, go to ftp.mozilla.org/pub/mobile/releases/ instead.
3. 3
   Select the version you want to install. For example, if you want to install version 100.3.0, tap 100.3.0.

   • Beta versions contain a "b" in their version numbers. Do not install the beta version if a non-beta release is available, as it may not work properly.
4. 4
   Select your Android's architecture. APKs are available for various processor types. If you're not sure which option to select, install an app like Droid Hardware Info and find the value of "CPU architecture" (e.g., ARM or x86).
5. 5
   Download the APK file. Tap the link for the APK version you want to install. This downloads the file to your Android.
6. 6
   Install the APK. Once downloaded, tap the APK in your downloads, then tap Install. This installs the downgraded version of Firefox on your phone or tablet.

   • If prompted, you may need to tap Settings or similar to allow installation of unknown apps from your file manager.
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Section 3 of 3:

Risks of Downgrading Firefox

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1. Running an older version of Firefox is risky. Even if you're not fond of the newest features (like AI) in the newer versions of Firefox, it's usually not worth downgrading. Here's why:

   • Mozilla frequently releases updates to Firefox to fix bugs and security vulnerabilities. Downgrading to an older version of Firefox means you won't have the latest security patches, which could leave your computer vulnerable to exploits.
   • Some websites will only be compatible with the latest versions of Firefox. You may not be able to access all features on some websites if you're not using the current version.

Community Q&A

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• Question

  I play on a game site and some of the games are still in Java. Firefox (prior to v42) was the only browser that worked. Tonight it upgraded itself. I did what the article said, but still can't play. What now?

  

  Community Answer

  Have you considered upgrading your Java version? In many cases, the reason certain browsers work is due to its compatibility with your Java version. You should be able to update it in "System Updates" on your computer.

  Thanks! We're glad this was helpful.
  Thank you for your feedback.
  If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow

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  Not Helpful 3 Helpful 2
• Question

  Installed 62.0 ESR, disabled browser updates, added some add-ons, closed browser. Relaunched browser which proceeded to automatically update 62.0 ESR to the dreadful Quantum browser. Any workaround?

  

  Arrogance

  Top Answerer

  Firefox 62 is Quantum. Everything from 57 on up is the Quantum codebase. Also, 62.0 is not an ESR release. That was 52.

  Thanks! We're glad this was helpful.
  Thank you for your feedback.
  If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow

  Yes No

  Not Helpful 2 Helpful 1

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Warnings

• Older Firefox versions often contain unpatched vulnerabilities that can be exploited by hackers to infect your system with malware or steal your personal information.
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