Web and Developer Tools
NoScript Security Suite Requires Restart Featured
The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.
Stylish Requires Restart
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Tumblr, and many, many other sites. You can even customize Firefox and other programs themselves.
User Agent Switcher Requires Restart
The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.
FoxyProxy Standard Requires Restart
FoxyProxy is an advanced proxy management tool that completely replaces Firefox's limited proxying capabilities. For a simpler tool and less advanced configuration options, please use FoxyProxy Basic.
Full Web Page Screenshots (♥♥♥♥♥) Requires Restart
FireShot makes full web page screenshots. Demo: http://bit.ly/RlBQMV
Screenshots can be quickly captured and:
― Saved as Image or PDF
― Sent to clipboard
― Annotated *
― Uploaded *
― E-Mailed *
* OS Windows only
This add-on is not compatible with your version of SeaMonkey because of the following:
- Add-on has opted into strict compatibility checking.
Web Developer Requires Restart
The Web Developer extension adds various web developer tools to the browser.
Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...
SQLite Manager Requires Restart
Manage any SQLite database on your computer.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
Live HTTP Headers Requires Restart
View HTTP headers of a page and while browsing.
As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.
Screengrab (fix version) Requires Restart
Screengrab! saves webpages as images.
New features: upload to internet
HttpFox Requires Restart
An HTTP analyzer addon for Firefox
Font Finder Requires Restart
FontFinder is created for designers, developers and typographers. It allows a user to analyze the font information of any element on a page, copy any piece(s) of that information to the clipboard, and perform inline replacements to test new layouts.
'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!
Open With Photoshop is a new companion for web and graphic designers to open up any web image with Adobe Photoshop via a single and quick mouse click.
Cookie Importer Requires Restart
Imports cookies from a textfile.
Reads Netscape standard cookies.txt files as exported by IE and others.
Very useful in combination with the Cookie Exporter add-on.
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.
NoRedirect Requires Restart
NoRedirect lets the user take control of HTTP redirects. It can be used to interdict an ISP's DNS search redirection hijacks, preview/screen "shortened" URLs (e.g., TinyURL), stop the annoying redirection of "smart" error pages, etc.