Is there any keyboard shortcut to switch JavaScript on/off in Firefox?
No, there isn't.
Here are two options:
- If you use the NoScript add-on, it uses ctrl-shift-backslash as the keyboard shortcut to toggle JS permissions for the main domain of the page. This is an imperfect solution, however, since many sites use JS from multiple domains.
- If you want something simpler, the JS Switch add-on gives you a toolbar button to do a full toggle of JS, but it doesn't appear to have a keyboard shortcut.