Starting Firefox 66, you can able to assign custom keyboard shortcuts to extensions in about: addons page. A two-year-old bug -” UI for reassigning an extensions command keyboard shortcut” – has been fixed by Mozilla and target milestone set to version 66.
If you’re a Chrome user, you already know the Google browser allows to assign custom shortcuts to installed extensions in chrome://extensions page, you can soon able to do that when Firefox reaches 66.
Assigning Custom keyboard shortcuts to extensions in Firefox
1. To get started, ensure you’re using latest Firefox nightly which to get support for dedicated profile -per install in version 67.
2. Click on Hamburger menu, select Add-ons > Extensions
3. Click on ‘keyboard extensions’ before gear icon,
4. Manage Extension Shortcuts UI shows shortcuts that extensions already using or empty input filed for you to assign new ones. You can click on a shortcut, and give a new shortcut to your liking. If extensions you installed don’t support shortcuts, the UI clearly informs that to the user that ‘There are no shortcuts for this extension’.
You can create new keyboard shortcuts for extensions by typing in the input field. Once done, next time without clicking on the extension icon on the toolbar, you can able to activate extension in Firefox by using the keyboard shortcut.
UPDATE January 28, 2019: Manage Extension Shortcuts option has been moved to gear menu in the add-ons manager.