How To Uninstall Firefox Completely

To uninstall Firefox completely from your Windows or macOS computer, you must remove not only the application itself but also the hidden profile data, registry entries, and temporary files it leaves behind. This guide provides the exact steps to purge every trace of Firefox, ensuring a clean slate for a fresh install or a switch to another browser, and the same principles apply when you uninstall a browser like Chrome or Edge. If you are preparing a Linux system instead, you can install Firefox on arch Linux with a single command.

Before you uninstall Firefox completely

Before you begin the removal process, it is critical to close Firefox entirely and back up your valuable data. Skipping this step can lead to data loss, as uninstalling the browser does not automatically delete your bookmarks, passwords, or browsing history, but manual cleanup steps later will.

1. Close all Firefox windows and processes: Click the X on all open Firefox windows. Then, open Task Manager (press Ctrl + Shift + Esc), find any Firefox.exe processes, and click End Task. This ensures no background processes interfere with the uninstaller.
2. Back up bookmarks and passwords: Open Firefox and press Ctrl + Shift + B to open the Library. Click Import and Backup > Backup... to save an HTML file of your bookmarks. For passwords, go to Settings > Passwords > Export to save a CSV file. Alternatively, sign in to a Firefox account and enable Sync to store your data in the cloud.

With your data safely backed up, you can proceed with the uninstallation on your specific operating system.

Uninstall Firefox completely on Windows

On Windows 10 and Windows 11, the standard uninstaller removes the main program files but leaves behind your profile, cache, and registry entries. Follow these steps to remove the application and then manually delete the remaining data.

Step 1: Uninstall via Settings or Control Panel

1. Press Windows + I to open Settings.
2. Navigate to Apps > Apps & features (on Windows 11, it is Installed apps).
3. In the search bar, type Mozilla Firefox.
4. Click the three-dot menu next to Firefox and select Uninstall. Confirm the prompt.
5. For older Windows versions (Windows 8/7), open Control Panel > Programs > Uninstall a program, select Mozilla Firefox, and click Uninstall.

If the uninstaller asks whether to remove your personal data, choose Remove if you do not need the backup (but you already backed up in the previous section).

Step 2: Delete leftover profile folders in AppData

Firefox stores your bookmarks, passwords, and settings in two separate locations. After the uninstaller finishes, these folders remain. You must delete them manually.

1. Open File Explorer and type %APPDATA%\Mozilla into the address bar, then press Enter. This opens the Roaming folder.
2. Delete the entire Mozilla folder. This contains your Profiles directory (e.g., xxxxxxxx.default).
3. Next, type %LOCALAPPDATA%\Mozilla into the address bar and press Enter. Delete the Mozilla folder here as well. This removes cache and temporary profile data.
4. Also check C:\Users\<username>\AppData\Local\Temp for any Firefox or Mozilla folders and delete them.

These two folders hold all user-specific data. Deleting them ensures no bookmarks, cookies, or saved passwords remain.

Step 3: Clean registry entries and temporary files

The Windows Registry retains references to Firefox even after uninstallation. Incorrect registry edits can harm your system, so proceed carefully.

1. Press Windows + R, type regedit, and press Enter to open the Registry Editor.
2. Navigate to HKEY_CURRENT_USER\Software\Mozilla. Right-click the Mozilla key and select Delete.
3. Navigate to HKEY_LOCAL_MACHINE\Software\Mozilla and delete the Mozilla key similarly.
4. Press Ctrl + F to open Find, type Firefox, and click Find Next. Delete any remaining keys or values containing "Firefox" (e.g., HKEY_CLASSES_ROOT\FirefoxHTML). Repeat until no more entries are found.
5. Close the Registry Editor.

To clear temporary files, type Disk Cleanup in the Windows search bar and open the tool. Select your system drive, check Temporary files and Cache, and click OK. This removes any residual Firefox cache stored outside the AppData folders.

Uninstall Firefox completely on macOS

On macOS, Firefox does not include a dedicated uninstaller. Dragging the app to the Trash leaves behind your profile and preference files. Use this manual process to remove everything.

Step 1: Drag Firefox to the Trash

1. Open the Applications folder in Finder.
2. Locate Firefox and drag it to the Trash icon in your Dock.
3. If prompted for an administrator password, enter it to confirm.

This removes the main application bundle but not your personal data.

Step 2: Delete profile data in the user Library

Firefox stores your profile (bookmarks, passwords, settings) in a hidden folder inside your user Library. You must remove it manually.

1. In Finder, press Shift + Cmd + G (Go to Folder) and type ~/Library/Application Support/Firefox. Press Enter.
2. Delete the Firefox folder. This contains your Profiles directory and the profiles.ini file.
3. Press Shift + Cmd + G again and type ~/Library/Preferences. Look for a file named org.mozilla.firefox.plist and delete it.
4. Go to ~/Library/Caches and delete the Firefox folder if it exists.
5. Check ~/Library/Saved Application State and delete org.mozilla.firefox.savedState if present.

These steps remove all traces of your Firefox profile, including saved passwords and browsing history.

Finish the cleanup

To ensure the uninstallation is fully complete, you must finalize the removal of the deleted items and restart your system.

1. Empty the Recycle Bin or Trash: On Windows, right-click the Recycle Bin and select Empty Recycle Bin. On macOS, right-click the Trash icon and choose Empty Trash. This permanently deletes all removed Firefox files.
2. Restart your computer: A restart clears any remaining memory-resident processes and ensures the registry and file system updates take effect.
3. Verify removal: After restarting, search your system for "Firefox" or "Mozilla" in File Explorer (Windows) or Finder (macOS). If no results appear, the uninstallation is complete.

By following these steps, you have successfully uninstalled Firefox completely. Your system no longer contains any browser data, registry keys, or temporary files, leaving it optimized for a fresh installation of Firefox or a different browser.