| BabelFish | | - | | |
| Bandcamp New Tab | | - | | |
| Bandcamp Volume | | - | | |
| Bandcamp Volume Slider | | - | | |
| Beautify | | - | | |
| Beautify Google | | - | | |
| Best Free Image Hosts | | - | | |
| Bestsellers and Search on Rakuten， Amazon and Yahoo! Shopping | | - | | |
| Better Gmail 2 | | - | | |
| Better MXR | | - | | |
| Bing Search for Firefox | | - | | |
| Bing to Duck redirect | | - | | |
| BitDefender QuickScanner | | - | | |
| Bitbucket Issues convenience | | - | | |
| Bitcoin Price Ticker | | - | | |
| Black Google Theme | | - | | |
| Black Skin | | - | | |
| Black Youtube Theme | | - | | |
| Blue Google Theme | | - | | |
| Booru Extractor | | - | | |
| Booru Extractor 3 | | - | | |
| Booru Slideshow | | - | | |
| Boorumate | | - | | |
| BrowsIn | | - | | |
| Bug | | - | | |
| BugMeNot | | - | | |
| BugzillaJS - Tweaks for Bugzilla | | - | | |
| BuiltWith Tab | | - | | |
| Button for Amazon | | - | | |
| CL Pics | | - | | |
| CacheIt! | | - | | |
| Calilay | | - | | |
| Camideo Video Search | | - | | |
| CenterTube | | - | | |
| Chain Duck | | - | | |
| Character Identifier | | - | | |
| Chicky's Booru-style Image Downloader | | - | | |
| Classic Retweet | | - | | |
| CleanTube | | - | | |
| Clearly | | - | | |
| Cleeki Firefox Express | | - | | |
| Cloud Clipboard | | - | | |
| CloudMagic | | - | | |
| CodeNav | | - | | |
| Color Change for Facebook | | - | | |
| Comeback Cached Link | | - | | |
| Contextual Google Image Search | | - | | |
| CookieRank | | - | | |
| CoolPreviews | | - | | |
| Copy Real Url | | - | | |
