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:
C:Users[YourUsername]AppDataRoamingMozillaFirefox 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:
C:Users[YourUsername]AppDataLocalMozillaFirefox 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:
HKEY_LOCAL_MACHINESOFTWAREMozilla HKEY_CURRENT_USERSOFTWAREMozilla 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:
| Location | What It Contains |
|---|---|
~/Library/Application Support/Firefox | Your profile data, settings, extensions |
~/Library/Caches/Firefox | Cached web content |
~/Library/Preferences/org.mozilla.firefox.plist | App preferences file |
~/Library/Saved Application State/org.mozilla.firefox.savedState | Window/session state |
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:
sudo apt remove firefox sudo apt purge firefox The purge flag removes configuration files that remove alone leaves behind.
For Fedora/RHEL-based systems:
sudo dnf remove firefox Remove the profile directory:
Regardless of how Firefox was installed, the profile lives at:
~/.mozilla/firefox/ Delete this directory to remove all user data. Some distributions also store cache at ~/.cache/mozilla/firefox/ — delete that folder too for a full cleanup.
Why This Matters for Reinstallation
If you're uninstalling Firefox specifically to fix a problem — crashes, slow performance, broken extensions — and plan to reinstall, a partial uninstall often just recreates the issue. The corrupted or misconfigured data in the profile survives the reinstall and loads right back in.
A complete removal followed by a fresh install gives Firefox nothing to inherit. It starts from factory defaults.
Conversely, if you want to keep your bookmarks and settings through a reinstall, you can back up just the profile folder before deleting it, then restore it after reinstalling. Firefox will recognize the existing profile on next launch.
The Variable That Shapes Your Next Step
What "completely uninstalling" means in practice depends on why you're doing it. Someone troubleshooting a corrupted install has different priorities than someone who's switching to Chrome permanently and wants every trace gone. A power user managing multiple Firefox profiles across work and personal browsing faces a different cleanup than someone who only ever had one profile.
The steps above cover the full scope — but which of them matter for your situation depends on your OS, how long you've used Firefox, whether you've ever set up a Firefox account, and what you're doing next.