Uninstalling add-ons

This article applies to Firefox and Thunderbird. Mozilla Suite and SeaMonkey users should read Uninstalling extensions - SeaMonkey.

Firefox and Thunderbird add-ons (extensions and themes) can be uninstalled using the Add-ons dialog.

1. Tools -> Add-ons
2. Click on the Extensions or Themes button on the top.
3. Click on the Extension or Theme you want to uninstall.
4. Click Uninstall.
5. Restart Firefox or Thunderbird.

Uninstalling an extension might not completely remove all of the extension's data. For example, if you reinstall the extension, then you might find that it still uses its previous settings. There is no general way to remove all of an extension's data.

Troubleshooting

If you have trouble uninstalling an add-on:

• Make sure you completely closed the application after clicking Uninstall by using the File menu and selecting "Exit". You can even restart your system to make absolutely sure.
• If something's wrong with your Firefox or Thunderbird that prevents you from accessing the Add-ons dialog, you can start it in Safe Mode to uninstall the add-on.
• If the uninstall button and menu item are disabled, the add-on is locked. To uninstall a locked add-on, you'll first have to unlock it via Safe Mode.
• The add-on repeatedly shows "This item will be uninstalled after you restart Firefox" even after restarting. In this case, do not use the uninstaller extensions. Either create a new profile or try uninstalling manually.
• If you're using Firefox or Thunderbird 1.5 and you have an entry that ends in ".xpi" and does nothing when clicking on it, delete the following files from your profile folder[1][2]:
  • extensions.cache
  • extensions.ini
  • extensions.rdf

Uninstalling an add-on manually - Advanced

Exit your Mozilla application, go to your profile folder and open the extensions directory. Each directory there is an extension. Remove the directory that corresponds to the add-on you want to uninstall. (To uninstall ALL add-ons, remove the entire extensions directory)

If an add-on directory there does not have a meaningful name, look inside it for its install.rdf file. Open that file in a text editor (such as Notepad) to see which add-on the directory contains. Alternatively, in the parent folder extensions.rdf contains a list of add-ons, their names and corresponding add-on GUIDs.

Global add-on

In rare cases, an add-on may be installed globally. Installing an add-on globally is something an administrator might do so that the add-on can be used by any user on the machine. To manually uninstall a global add-on, open the add-ons directory in the installation directory's and remove the directory that corresponds to the add-on you want to uninstall.[3]