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.
"Restart" menu and button, with configurable shortcut key.
Minimum and fast URL blocker.
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
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
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.
Search with Joy! Block Ads While Surfing!
All the great features of /u/RemindMeBot in a quick and easy to use extension!
Crash yourself with ease
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.
Avoid redirects and has direct access to the sites you want to visit.
Adds an about:addons-memory page that details add-on memory usage
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.
With MyAdFilter, free content creators propose you only one ad. Apart from those, as your usual ad-blocker, MyAdFilter disables all ads.
Rewrite http response body using search & replace patterns