Warning: Firefox now includes downgrade protection to prevent corruption of user profile data. If you install an older version, you'll be prompted to create a new Firefox profile.
Free Firefox 51
If there is a problem with a Firefox version, most people will try to revert Firefox back to the way it was before and downgrade it, but we do not recommend this action. Downgrading Firefox leaves a user more vulnerable to attacks and, on most occasions, doesn't fix the problem that occurred while updating. This article gives you some alternatives to downgrading and links to old versions of Firefox, if you do choose to downgrade.
Global ActivClient ” for 64bit Firefox or “C: Program Files (x86) HID Global ActivClient ” for 32bit versions of firefox. Select the acpkcs211.dll and click Open. Finally click the OK button. WebDriver for Firefox. Contribute to mozilla/geckodriver development by creating an account on GitHub. Mozilla Firefox 51.0.1 Change Log Fixed: Multiprocess incompatibility did not correctly register with some add-ons (Bug 1333423) Geolocation not working on Windows (Bug 1333516).
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Problems with an update are generally not caused by the new version of Firefox, but rather the update process. Installing a previous version will not help in most cases. Instead, see:
Note: Other problems can be solved with the Refresh Firefox feature. It restores Firefox to its default state while saving your essential information.
Ensure all security and security-related software is fully updated. Some security software will need to be upgraded to a new version for each Firefox version update.
![Download Download](/uploads/1/2/6/3/126362860/991237039.png)
Optional software bundled with security software may also need updating. Such software may not be essential for your security, but if outdated, it may interfere with the use of Firefox, or cause Firefox to crash.
If you want to downgrade, you can visit Mozilla's directory of older Firefox versions using the link below. Please note, however, that using older versions of Firefox can be harmful and that we recommend you use the newest version of Firefox. Warning: Old Firefox versions pose a significant security risk.
- Firefox 67.0.432-bit (US English)
- Firefox 67.0.464-bit (US English)
- Firefox 67.0.432-bit (US English)
- Firefox 67.0.464-bit (US English)
- Firefox 68.0.232-bit (US English)
- Firefox 68.0.264-bit (US English)
- Firefox 68.0.232-bit (US English)
- Firefox 68.0.264-bit (US English)
- Firefox 69.0.332-bit (US English)
- Firefox 69.0.364-bit (US English)
- Firefox 69.0.332-bit (US English)
- Firefox 69.0.364-bit (US English)
- Firefox 70.0.132-bit (US English)
- Firefox 70.0.164-bit (US English)
- Firefox 70.0.132-bit (US English)
- Firefox 70.0.164-bit (US English)
- Firefox 71.032-bit (US English)
- Firefox 71.064-bit (US English)
- Firefox 71.032-bit (US English)
- Firefox 71.064-bit (US English)
- Firefox 72.0.232-bit (US English)
- Firefox 72.0.264-bit (US English)
- Firefox 72.0.232-bit (US English)
- Firefox 72.0.264-bit (US English)
- Firefox 73.0.132-bit (US English)
- Firefox 73.0.164-bit (US English)
- Firefox 73.0.132-bit (US English)
- Firefox 73.0.164-bit (US English)
- Firefox 74.0.132-bit (US English)
- Firefox 74.0.164-bit (US English)
- Firefox 74.0.132-bit (US English)
- Firefox 74.0.164-bit (US English)
- Firefox 75.032-bit (US English)
- Firefox 75.064-bit (US English)
- Firefox 75.032-bit (US English)
- Firefox 75.064-bit (US English)
- Firefox 76.0.132-bit (US English)
- Firefox 76.0.164-bit (US English)
- Firefox 76.0.132-bit (US English)
- Firefox 76.0.164-bit (US English)
- Firefox 77.0.132-bit (US English)
- Firefox 77.0.164-bit (US English)
- Firefox 77.0.132-bit (US English)
- Firefox 77.0.164-bit (US English)
- Firefox 78.0.232-bit (US English)
- Firefox 78.0.264-bit (US English)
- Firefox 78.0.232-bit (US English)
- Firefox 78.0.264-bit (US English)
- Firefox 79.032-bit (US English)
- Firefox 79.064-bit (US English)
- Firefox 79.032-bit (US English)
- Firefox 79.064-bit (US English)
- Firefox 80.0.132-bit (US English)
- Firefox 80.0.164-bit (US English)
- Firefox 80.0.132-bit (US English)
- Firefox 80.0.164-bit (US English)
![Firefox Firefox](/uploads/1/2/6/3/126362860/108574186.png)
- Firefox 81.0.232-bit (US English)
- Firefox 81.0.264-bit (US English)
- Firefox 81.0.232-bit (US English)
- Firefox 81.0.264-bit (US English)
Important: By default, Firefox is set for automatic updates. To prevent Firefox from automatically updating itself after you install an older version, you'll need to change your Firefox update settings: Click the menu button and select .. In the General panel, go to the Firefox Updates section.
Instead of downgrading to an older, insecure version of Firefox and changing your update settings, you should consider these alternatives:
Install Firefox Extended Support Release.Firefox Extended Support Release (ESR) is an official version of Firefox developed for large organizations like universities and businesses. Firefox ESR does not come with the latest features but it has the latest security and stability fixes. For more information, see the article Switch to Firefox Extended Support Release (ESR) for personal use.
Use the latest version of another browser. If the current Firefox version is not to your liking or just not working right now, there are alternative browsers that you can use to browse the web.
Firefox 51 Download Mac
If the latest version of Firefox is causing problems for you or you just don't like something about it, please give us feedback about it here: