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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.

Rated 4 out of 5 stars (75)
27,659 users

Tiny JavaScript Debugger Requires Restart

TinyJSD is a JavaScript debugger for privileged code running Mozilla products like Firefox, Thunderbird, SeaMonkey. It serves to debug the application as well as extensions written in JavaScript.

Rated 4 out of 5 stars (8)
26,461 users

ShowIP Requires Restart

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.

Rated 3 out of 5 stars (277)
25,458 users

WorldIP - Geo Add-on with Security Features Requires Restart

Professional Geo Add-on with security features and advanced network tools. Anti-phishing. Protection against DNS spoofing and fake sites. All DNS records for domain. The real location of web server, country flag, extended information about datacenter

Rated 5 out of 5 stars (117)
21,869 users

Open With Requires Restart

Quickly test out your web pages in Internet Explorer, Chrome, Safari, or Opera. Open With opens the current page in your other browsers with just one click. Add Open With to your menus, toolbars and developer toolbox today!

Rated 4 out of 5 stars (160)
19,455 users

Form History Control Requires Restart

Manage form history entries (search, edit, cleanup, export/import) and easy text formfiller.

Auto-save text entered in any form while typing to allow fast recovery when disaster strikes.

Control for which webpage form history is saved or not.

Rated 5 out of 5 stars (93)
18,541 users

Firesizer Requires Restart

Allows you to resize the window to specific dimensions.

NOTE: Users of Firefox 29 and above must install "The Addon Bar" extension to use this, as Firesizer uses the add-on bar that has been removed in Firefox 29.

Rated 4 out of 5 stars (126)
17,670 users

FoxyProxy Basic Requires Restart

FoxyProxy Basic is a simple on/off proxy switcher. More advanced features and configuration options are offered by FoxyProxy Standard.

Rated 4 out of 5 stars (31)
16,949 users

RequestPolicy Requires Restart

Be in control of which cross-site requests are allowed. Improve the privacy of your browsing by not letting other sites know your browsing habits. Secure yourself from Cross-Site Request Forgery (CSRF) and other attacks.

Rated 4 out of 5 stars (205)
15,848 users

Nightly Tester Tools Requires Restart

Useful tools for the nightly tester.

Rated 4 out of 5 stars (186)
15,843 users

Linkification Requires Restart

Converts text links into genuine, clickable links...

Rated 4 out of 5 stars (283)
15,233 users

Dafizilla Table2Clipboard Requires Restart

Mozilla applications allow to select rows and columns from a table simply pressing Control key and picking rows/columns with left mouse button.
The selection can be copied to clipboard but the original table disposition is lost making ugly results wh...

Rated 5 out of 5 stars (65)
13,800 users

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.

Rated 4 out of 5 stars (54)
12,790 users

Restartless 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.

Rated 4 out of 5 stars (201)
12,265 users

Open With Photoshop

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.

Rated 5 out of 5 stars (70)
12,261 users

PrefBar Requires Restart

The all in one toolbar(item). Houses and manages bigger amounts of buttons (Clear Cache, Clear Cookies, ...), Menus (User Agent spoof...) and checkboxes (Javascript, Flash, ...). Extensible from online-database or with self created buttons.

Rated 5 out of 5 stars (41)
11,629 users

about:addons-memory 2016

Adds a new page that shows add-on memory usage

Rated 5 out of 5 stars (33)
11,155 users

RequestPolicy Continued

Be in control of which cross-site requests are allowed. Improve the privacy of your browsing by not letting other sites know your browsing habits. Secure yourself from Cross-Site Request Forgery (CSRF) and other attacks.

Rated 4 out of 5 stars (13)
6,372 users

Live HTTP Headers (clone)

View HTTP headers of a page and while browsing.

This is an unofficial "Live HTTP headers" clone, mainly to fix the Replay feature!

Rated 4 out of 5 stars (9)
5,071 users

Re-Pagination

See more search results etc. on one page, concatenating several pages together...

Rated 4 out of 5 stars (56)
4,805 users