Adds an ‘install’ button to the add-ons manager.
Compatibility 
- Works with: Firefox 3.6
Background
For safety reasons Mozilla has disabled the install button in the add-ons manager. The reasoning behind this is most Firefox users should be installing add-ons from the official repository (AMO) or from a trusted site. But what about users who have backups of their add-ons saved locally? They could drag and drop the add-on file into the add-ons manager.
The Tweak
The ‘install’ button allows users to browse their computer to locate the add-on they want to install. Keep in mind is always best to get add-ons through addons.mozilla.org whenever possible as these add-ons already have undergone a review process before made available and updates are served through a secure connection. Also, since it is already whitelisted there is no need to grant further access to other web sites. A simple edit will enable to Install button in the add-ons manager:
- Enter about:config in the location bar to access the advanced preferences
- Filter for extensions.hideInstallButton
- Double click the entry to change it to false
Notes
- Firefox 4.0, and newer has a visible ‘Install add-on from file’ option via the ‘Gear’ button (next to the search box in the upper-right corner) in the add-ons manager
Updated: November 15, 2025
