FAQ: How can I disable safe mode on Firefox?

Completely disabling safe mode on Firefox is far from easy. You basically have to hack your Firefox installation, which requires a significant level of technical know-how. However, there are two relatively easy steps you can take to make it more difficult to start Firefox in safe mode.

Remove the Help Menu Item

You can use the userChrome browser customization file to remove the “Restart with Add-ons Disabled” menu item from the Help menus. Carefully follow these steps:

  • Locate your Firefox profile folder.
  • Create a new folder chrome inside your profile folder (if it doesn’t already exist).
  • Create a new file userChrome.css inside that folder with the following content: [label^='Restart with Add-ons Disabled'] { display: none !important; }

You will need to close all Firefox windows and restart Firefox for it to take effect.

Note: If you’re using Firefox 69 or above, you’ll also need to go to about:config and ensure the toolkit.legacyUserProfileCustomizations.stylesheets preference is set to true (go here for more detailed instructions).

(Credit to Metaception for suggesting this solution.)

If you also want to remove the button from the about:support and about:profiles pages, create another file userContent.css inside the same folder with the following content:

#safe-mode-box { display: none !important; }
#restart-in-safe-mode-button { display: none !important; }

If you also want to remove the “Create a New Profile” button from the about:profiles page, add the following line to userContent.css:

#create-button { display: none !important; }

Disable the Safe Mode Key

You can set the environment variable MOZ_DISABLE_SAFE_MODE_KEY (to any value) to prevent starting Firefox in safe mode by holding down the SHIFT key.

If you’re not sure how to set an environment variable, you can find guidance here.