How to Delete Firefox Plugins After Uninstalling the browser

Mozilla Firefox is one of the most popular web browsers, known for its speed, flexibility, and vast ecosystem of plugins and extensions. While uninstalling Firefox itself is a fairly straightforward process, many users are surprised to find traces of it—especially plugins and extension data—lingering on their systems afterward. This residual data can consume disk space, pose privacy risks, or even interfere with future browser installations. In this article, we provide a comprehensive guide on how to permanently delete Firefox plugins and associated data after you’ve uninstalled the browser.

TL;DR (Too Long; Didn’t Read)

Uninstalling Firefox does not remove all plugins or their related configuration files from your system. To fully remove these plugins, you’ll need to manually delete hidden folders and registry entries, depending on your operating system. The process includes checking user profile directories, clearing cache files, and cleaning up leftover registry keys. Follow our complete step-by-step guide below to ensure your system is completely free of Firefox-related plugin residues.

Why Removing Plugins Matters

Even when Firefox is no longer installed, leftover plugins may still be active components on your system under an add-on framework or saved profile. Some developers bundle additional utilities with plugins, which could run independently of Firefox, retain personal data, or even cause system slowdowns. Ensuring complete removal helps maintain:

• Privacy: Some plugins may store browsing data and usage logs.
• Security: Outdated plugins could be vulnerable to exploits even without an active browser.
• System Organization: Removing these files keeps your system clean and reduces clutter.

Step-by-Step Guide to Removing Firefox Plugins After Uninstalling

Step 1: Check for Hidden Profile Folders

When Firefox is installed, it creates profile folders where extensions and plugin-related data are stored. These folders are not deleted automatically when you uninstall the browser.

On Windows:

• Press Windows + R, type %APPDATA%\Mozilla\Firefox\ and hit Enter.
• Look for folders named Profiles and delete them.

On macOS:

• Open Finder, press Command + Shift + G and enter: ~/Library/Application Support/Firefox/
• Delete the Profiles directory found there.

On Linux:

• Open a terminal and navigate to ~/.mozilla/firefox/
• Use the command rm -rf ~/.mozilla/firefox/ to delete the folder.

Step 2: Locate and Remove Plugin Folders

Some plugins are installed in system directories and must be removed manually. Well-known directories used by plugins include:

• Windows: C:\Program Files\Mozilla Firefox\plugins (or Program Files (x86) on 64-bit systems)
• macOS: /Library/Internet Plug-Ins and ~/Library/Internet Plug-Ins
• Linux: /usr/lib/mozilla/plugins or ~/.mozilla/plugins

Delete any entries related to previously installed Firefox plugins. If unsure about a file or folder, a quick web search for the file name can help identify its purpose.

Step 3: Clean Cached Extension and Plugin Data

Firefox and its plugins often store cached data that remains even after uninstallation. These files might be located in different system or user-level cache directories.

Clear the following directories:

Windows:

C:\Users\YourName\AppData\Local\Mozilla
C:\Users\YourName\AppData\Roaming\Mozilla

macOS:

~/Library/Caches/Firefox
~/Library/Application Support/Mozilla

Linux:

~/.cache/mozilla
~/.mozilla

After deleting these folders, empty your system’s Trash or Recycle Bin to ensure permanent removal.

Step 4: Remove Firefox Plugin Registry Entries (Windows Only)

On Windows systems, Firefox plugins may leave behind registry entries. Cleaning these helps prevent future conflicts and ensures no autoloading of old plugin settings. Editing the registry should be done carefully, as mistakes can harm your system.

Steps:

1. Open the Run dialog via Windows + R, type regedit, and press Enter.
2. Navigate to: HKEY_LOCAL_MACHINE\Software\MozillaPlugins
3. Delete all subkeys related to uninstalled Firefox plugins.

Also check:

• HKEY_CURRENT_USER\Software\Mozilla
• HKEY_LOCAL_MACHINE\Software\Mozilla

Before editing the registry, we strongly recommend creating a system restore point.

Step 5: Use a Specialized Uninstaller or Cleaning Tool

If you’re not comfortable deleting files or editing the registry manually, a trusted third-party uninstaller can automate the cleanup. Consider tools like:

• Revo Uninstaller
• IObit Uninstaller
• CCleaner (free version is usually sufficient)

These utilities scan for leftover files, folders, and registry entries even after the application has been removed. Be sure to download them from their official websites to avoid bundled malware.

Important Considerations

• Backups: Before deleting anything, especially from the registry or system folders, back up your data or create a restore point.
• Shared Plugins: Some plugins, such as Java or Flash (where still applicable), may be used by multiple applications and not just Firefox. Make sure the plugin isn’t needed elsewhere before deleting.
• Reinstalling Firefox: If you plan to reinstall Firefox later, wiping all data might lead to a reset experience without any saved passwords, bookmarks, or extensions. Export those first if needed.

Verifying Successful Removal

To confirm that all Firefox-related plugins and residual data have been removed, follow these final checks:

1. Search for Firefox-related folders: Use your operating system’s search function to look for any files or folders named “Mozilla”, “Firefox”, or specific plugin names.
2. Check browser plugin directories: In any other browsers installed on your system, open their internal plugin management page and ensure there are no Firefox leftovers listed.
3. Review system performance: If the original motivation for uninstalling Firefox or its plugins was slowness or high CPU usage, use Task Manager or Activity Monitor to ensure the issue has been resolved.

Conclusion

Uninstalling Firefox is only half the job when it comes to truly removing its impact on your system. Plugins and their associated data can linger in various folders and the registry, cluttering your system and potentially compromising privacy. Though manual deletion takes a bit of effort, our step-by-step method helps ensure complete and secure removal of all Firefox plugins. By following this guide, you’ll not only free up space but also maintain a safer and more streamlined computer environment.