To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!Close
Welcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.Close
Show the IP address of the current page in the status bar. It also allows querying custom information services by IP (right click) and see location and avaiable vouchers for shopping sites. Additionally you can copy the IP address to the clipboard.
HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla. The number of errors of a HTML page is seen on the form of an icon
For Online HTML 5 validation, you need 0.962
Embeds Internet Explorer(IE) to use the powerful Firefox add-ons.
Not only an enhanced IE Tab, but also an enhanced Internet Explorer with Adblock Plus and FireGestures support.
Switch to the IE engine in one click and dismiss your IE.
this add-on simulates japanese mobile device.
this add-on support DoCoMo, Au(KDDI) and SoftBank device.
Extended Statusbar No Restart
A Statusbar with speed, percentage, time and loaded size (similar to Opera's one)
FirePHP enables you to log to your Firebug Console using a simple PHP method call.
Not using Firebug 1.9+ on Firefox 8+? See http://firephp.org/
A developer tool for interacting with web services and other web resources that lets you make HTTP requests, set the entity body, and content type. This allows you to interact with web services and inspect the results...
Classic Toolbar Buttons No Restart Featured
'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 on Windows.
Beta builds on versions page!
Restartless Restart No Restart
This 15KB restartless add-on will add a "File" -> "Restart" menu item and a ctrl/cmd + alt + r hotkey to restart Firefox or Seamonkey.
Advanced Cookie Manager Featured
A must have tool for Web Developers and Testers to Manage and monitor web cookies.
Export / Backup
Import / Restore
Available in English, French, Spanish, German and Italian languages.
1) Capture an page or just a specific region.
2) Adds a right click option to take screen shots of an entire web page or just part of a web page to save as an image.
Get SEO metrics while you surf! For each page you visit, see metrics like Domain and Page Authority, analyze links, expose page elements, and access other SEO tools. Next version will be for both Firefox and Chrome. Stay tuned!(This is version 2.6.5)
about:addons-memory No Restart
Adds an about:addons-memory page that details add-on memory usage
Selenium IDE is an integrated development environment for Selenium tests. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests.
User-Agent Switcher No Restart Featured
Quickly and easily switch between popular user-agent strings.
Font Finder Featured
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.
Search by Image for Google No Restart
Google Search by Image:
Use rightclick on an image to quickly find out the source of an image, how it is used, or find higher resolution versions via Google Reverse Image search.
(Google Image Search is similar to Tineye Reverse image search).
Auto Refresh will refresh or hard refresh any tab or group of tabs at individual or group intervals.
You can also customize your presets and save the ones you most use.