Up & Coming Extensions
Complete YouTube Saver Requires Restart
Download YouTube videos in various formats including 1080p, 4K etc (DASH formats). Convert audio track from videos to MP3 or WAV, or save audio in native format (Ogg, AAC/M4A, MP3, OPUS). Save YouTube page, video, comments and subtitles to one folder
CS Lite Mod Requires Restart
CS Lite allows you to set the permission of the cookie every domain from toolbar.
FiltaQuilla Requires Restart
Adds many new mail filter actions - launch a file, suppress notification, remove star or tag, mark replied or unread, copy as "read", append text to subject.
Keychain Services Integration Requires Restart
Store usernames and passwords in your Mac OS X Keychain.
Join-NG Requires Restart
Join partial messages. Somewhat similar to MS Outlook Express "combine and decode".
ThreadKey Requires Restart
Strike the 'T' key to sort messages by thread, strike the 'U' key to sort them unthreaded again, just like the 'G' key switches to Grouped By Sort view
Toggle Word Wrap Requires Restart
Toggle word wrapping and PRE element wrapping in the message composition and HTML display windows, respectively.
Adds an about:addons-memory page that details add-on memory usage
Open about:config to change hidden settings that cannot be edited from the Options window. All Mozilla based programs have settings that can not be changed in the options window.
Filter Uploader for Adblock Plus (unofficial) Requires Restart
DOES NOT BLOCK ADS! Don't install this add-on if you don't know what 'uploading' means!
This add-on Uploads the filters from your Adblock Plus installation to a FTP, HTTP, HTTPS server...
Compact Menu 2 Requires Restart
Add a compact menu button to the navigation toolbar, and hide the menu bar.
PrefBar Requires Restart
Email This! Requires Restart
Email This! will send your recipient the link, title, & highlighted text of the page you are viewing using GMail, Google Apps GMail, Yahoo, and Stand-Alone Mail Clients like Outlook Express, Thunderbird, & More!
Clean Subject Requires Restart
"Clean Subject" cleans the subject from multiple occurrences of subject prefixes such as ("Re: Re-2: Re:") and postfixes that are inserted by other clients. Words like "[SPAM]" can be cleaned as well. These prefixes can be defined in the preferences.
'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7s small view, Fx 4-12s large view & Tb 5-14) for current Firefox, Thunderbird and Seamonkey versions.
Beta builds on versions page!
Shrunked Image Resizer Requires Restart
Make your photos smaller, so they don't take forever to email or send to websites.
This extension is not being converted to a WebExtension.
Allow HTML Temp Requires Restart
This Add-on allows to have HTML temporarily allowed in the currently displayed message by only one click. When switching to another message, it'll be shown automatically again in plain text or simple html mode (if this is your default mode).
Text2Link Requires Restart
Text2Link is a simple and easy-to-use way to copy the text of a link, or to open URLs and send emails to addresses not marked-up as HTML links.
Fireclam Requires Restart
Use ClamAV to scan Firefox downloads for viruses.