How to Completely Uninstall Firefox From Your Computer

Most users assume dragging Firefox to the trash or clicking "Uninstall" is enough. It isn't. A standard uninstall removes the main application but leaves behind profile data, cached files, preference settings, and registry entries that can accumulate over time or interfere with a clean reinstall. A complete uninstall means removing all of it.

Here's what that actually involves — and why the process differs depending on your operating system and how you've used Firefox.

What a Standard Uninstall Leaves Behind

When you uninstall Firefox through the default method on any OS, the application itself is removed, but Firefox intentionally preserves your user profile. This profile contains:

• Bookmarks, history, and saved passwords
• Extensions and themes
• Cookies and site data
• Customized settings and user preferences
• Cached files and offline storage

This design is deliberate — Mozilla assumes you might reinstall and want your data back. But if you're troubleshooting a corrupted install, switching browsers permanently, or doing a clean slate reinstall, these leftovers need to go too.

How to Completely Uninstall Firefox on Windows 🖥️

Step 1 — Run the standard uninstall

Go to Settings > Apps > Installed Apps, find Mozilla Firefox, click the three-dot menu, and select Uninstall. Follow the prompts.

Step 2 — Delete the Firefox profile folder

Open File Explorer and navigate to:

The AppData folder is hidden by default. To see it, enable Show hidden items in the View menu, or type %AppData%MozillaFirefox directly into the address bar and press Enter.

Delete the entire Firefox folder inside the Mozilla directory.

Step 3 — Remove local cache data

Navigate to:

Delete this folder as well. This contains cached content that doesn't sync to the profile but still takes up disk space.

Step 4 — Clean the Windows Registry (optional but thorough)

Open the Registry Editor by pressing Win + R, typing regedit, and pressing Enter. Search for any remaining entries under:

Delete the Mozilla keys if they exist. Use caution with the registry — only delete keys you can clearly identify as Firefox-related. If you're not comfortable with this step, a tool like Revo Uninstaller can handle it automatically during the uninstall process.

How to Completely Uninstall Firefox on macOS 🍎

Step 1 — Quit Firefox completely

Make sure Firefox isn't running. Right-click the Dock icon and choose Quit, or use Cmd + Q while Firefox is active.

Step 2 — Move Firefox to Trash

Open your Applications folder, drag Firefox to the Trash, and empty it.

Step 3 — Remove profile and support files

Firefox stores its data in several locations on macOS. Open Finder, press Cmd + Shift + G to open the Go To Folder dialog, and check each of these paths:

Delete any Firefox-related folders or files in each of these locations.

How to Completely Uninstall Firefox on Linux

On most Linux distributions, Firefox is installed either through the system package manager or as a manual download.

If installed via package manager:

For Debian/Ubuntu-based systems, run: