Most Popular Extensions
Dorando keyconfig Requires Restart
A modified Dorando's addon to rebind keyboard shortcuts. It is designed to be a drop-in replacement, keeping your old settings. (See details for upgrade instructions.)
Get a faster browsing experience by blocking nasty web resources using Bluhell Firewall, the lightweight Ad-Blocker and Tracking/Privacy Protector.
Minimum and fast URL blocker.
"Restart" menu and button, with configurable shortcut key.
No need flash plugin on embeded youtube movies
UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.
Block advertisement and access to adult sites
Search with Joy! Block Ads While Surfing!
Crash yourself with ease
All the great features of /u/RemindMeBot in a quick and easy to use extension!
Deny resource:// access to Web content: We fill the hole to defend against fingerprinting. Very important to Firefox privacy. A direct workaround for bugzil.la/863246
Cleans your Firefox, Thunderbird, SeaMonkey, Fennec (unstable), Instantbird and BlueGriffon.
Important note: This extension will not work in Firefox 57 and above. Providing this functionality in Firefox is no longer possible, the extension is discontinued.
Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.
Adds an about:addons-memory page that details add-on memory usage
Generate e-bay templates online - in few minutes.
Avoid redirects and has direct access to the sites you want to visit.
lolifox - Fierr MOD Requires Restart
Replaces the error page with a lolifox appearance with additional features.
InfoNotary Configurator for Mozilla Requires Restart
Configures Mozilla for work with certificates issued by InfoNotary Plc.
Rewrite http response body using search & replace patterns