Hey…remember Firefox? Google Chrome is now king of the browser hill, but Firefox is still chugging along and is actually still the best browser for web app developers to use. Sure it’s a little slow and hard on memory, but its customization options can’t be beat. Take a look at all these great Firefox Add-ons for developers!

All reviews are taken directly from the Firefox add-on pages. Please excuse the spelling/grammar!

Best Firefox Add-ons – Web Developer Tools

This is where Firefox truly shines. There are a number of Add-ons available for just about any type of web development, and added bonuses like direct FTP capabilities within the browser!

Fire FTP

best firefox add-ons for developers

A fast and secure FTP client right in your browser!

Add-on User Review:

Rated 5 out of 5 stars

by Rudi on October 1, 2012 · permalink

One of most important add-ons on my Firefox. Many thanks for this perfect FTP.

Firebug

best firefox add-ons for developers

Edit, monitor, and debug any CSS, HTML, and JS live on a web page. It’s perfect for diagnosing those little errors on a live site.

Add-on User Review:

every web developer must have this super add-on Rated 5 out of 5 stars

by Keanu on February 14, 2013 · permalink

it’s a great add-on, best of the best. i don’t know how i lived without it before. special thanks for Net functions. i use wireshark before but now i can see everything with firebug, even much more. of course it need lot of memory, but this is not the problem for such great tool, really. there are lot of addons for web developers but this is really the best, if you have firebug you don’t need anothers. there are all their functions in this one and i don’t joke! in the begining you can think it’s not user-friendly, has lot of unnecessary functions, but later you will understand that you were not right and all these functions are really helpful and you need them. amazing tool, i’m pretty sure developers will be in paradise after die lol

Web Developer

best firefox add-ons for developers

Adds a wealth of great web development tools to your browser.

Rated 5 out of 5 stars

by smartmoneyman on January 16, 2013 · permalink

Most everything you’d ever want at your fingertips while developing your site! Exceptional!
Now all I want is for it to include a code generator, WYSIWYG editor and a mind reader so it can just create my sites as I think about them. I’ll give him a couple months to put that together, but I’ll bet he’s already heading in that direction.

Javascript Debugger (Venkman)

A powerful JS debugging environment for Firefox.

Add-on User Review:

Rated 5 out of 5 stars

by Mingyi Liu on March 25, 2012 · permalink

I used to use ChromeBug to debug for addons, but it only works with FF5 and lower. Venkman is no longer updated but it still works with FF13.0a2 as I tested. There’s some quirks when using it to debug, and its UI is not as well designed as ChromeBug (heck, even the webkit’s Developer Tools is inferior to Fire/ChromeBug’s UI), so if you only debug JS on webpages, use Firebug instead.

For addon debug though, Venkman still works with the latest FF and helps a lot. Thank you very much! Saves me quite some time.

SQLite Manager

best firefox add-ons for developers

Manage SQLite databases right from your browser

Add-on User Review:

Quick, light, simple Rated 5 out of 5 stars

by ChrisWellington on December 11, 2012 · permalink

Excellent for quick visual inspections and for debugging SQLite databases. Hardcore management of databases is probably best done elsewhere, but this has saved me lots of time by letting me watch progress as other programs interact with a database.

FirePHP

best firefox add-ons for developers

Quickly and easily debug code without interfering with live content. Perfect for AJAX developers.

Add-on User Review:

Rated 5 out of 5 stars

by Gastón Nina on December 15, 2012 · permalink

FirebugPHP is the best form to show logs in developing servers. This is awesome!!!

FlashFirebug

best firefox add-ons for developers

Debug any SWF file you come across on the web.

Add-on User Review (there are only 2 reviews, but 60,000 users):

isometricx Rated 5 out of 5 stars

by isometricx on May 11, 2010 · permalink

Very useful, thanks :)

JavaScript Deobfuscator

best firefox add-ons for developers

Watch and debug JS as it is compiled/executed on the page.

Add-on User Review:

Rated 5 out of 5 stars

by Alexander D. on August 12, 2012 · permalink

A must have add-on for security researchers and hardcore developers.

FireQuery

best firefox add-ons for developers

Created specifically to help jQuery Developers.

Add-on User Review:

Rated 5 out of 5 stars

by paper1337 on May 15, 2012 · permalink

An excellent addition to FireBug that easily allows you to browse events attached to elements, amongst other useful things. Worth downloading.

CacheViewer Continued

best firefox add-ons for developers

See when a file was last fetched on the server.

Add-on User Review:

A must have addon Rated 5 out of 5 stars

by mark27 on January 29, 2013 · permalink

An excellent,must-have addon for saving stuff hidden somewhere in the browser’s cache:thanks for the effort of keeping up with Firefox’s frantic development cycle.

Empty Cache Button

best firefox add-ons for developers

Quickly and easily empty your browser’s cache with the click of a button.

Add-on User Review:

Works great, looks great, I love it Rated 5 out of 5 stars

by Tomás on January 11, 2013 · permalink

Works as advertised and I appreciate the fine-grained configurable options – which caches to clear, whether or not to show a notification, and what to reload after cache has been cleared.Also like the attractive, minimalist toolbar button which doesn’t uglify my browser. Thanks!

Wappalyzer

best firefox add-ons for developers

Identify how a website has been built, and the systems it runs on.

Add-on User Review:

Rated 5 out of 5 stars

by Jeriff Cheng on December 27, 2012 · permalink

Great addon! It helps me identify which CMS the website is using,and I found so many beautiful websites are using WordPress.

CodeBurner for Firebug

best firefox add-ons for developers

HTML and CSS reference tools added right to the Firebug add-on to make it even more useful.

Add-on User Review:

Rated 4 out of 5 stars

by Julian Knight on March 5, 2009 · permalink

Very useful to part-time developers like myself.
What would get it 5-stars would be an equivalent lookup for JavaScript!

Best Firefox Add-ons – Web Development Testing

You can also use Firefox Add-ons to debug and test all your development work!

YSlow

best firefox add-ons for developers

See why a website is performing so slowly.

Add-on User Review:

Perfect addon for page performance improvement Rated 5 out of 5 stars

by Jeriff Cheng on December 27, 2012 · permalink

Perfect addon for page performance improvement, I use it for webpage analysis, like how many js and css files are loaded and find way to optimize the page speed, perfectly combination with Google Pagespeed addon.

FoxyProxy

best firefox add-ons for developers

Advanced proxy management for Firefox.

Add-on User Review:

Rated 5 out of 5 stars

by bike racks for cars on October 7, 2012 · permalink

Hi use FoxyProxy from a lot of time and I really appreciate its features. I usually switch proxy using that “foxy” icon placed on the lower right of the window: you can just right click on it, select the desired proxy and you’re ready to do what you want. Fast and simple enough.
It also comes with some good configuration options, too. As I said in title, FoxyProxy is a clever and nice tool, for web testers and other kind of people. Well done Jung!

User Agent Switcher

best firefox add-ons for developers

Adds a button to quickly switch your browser’s user agent.

Add-on User Review:

for css design Rated 4 out of 5 stars

by Popury Mhyels on July 7, 2012 · permalink

this addon is Very helpful! , im just another web designer ( CSS )

HttpFox

best firefox add-ons for developers

Analyzes HTTP traffic between browser and server.

Add-on User Review:

Well done Rated 5 out of 5 stars

by Flansch on January 26, 2013 · permalink

Although modern web developer tools like Firebug include http tracing, I personally prefer Httpfox because of it’s better arrangement of the information. Everything stays in the same location for each request/response and you can see full URLs without hovering over the entries, while in Firebug have to do a lot of scrolling and clicking to see what’s going on.
Unfortunately there’s few activity in including new features.

Poster

best firefox add-ons for developers

Interact with web services and send HTTP requests to view the results. Great for debugging.

Add-on User Review:

Rated 5 out of 5 stars

by yossishm on June 30, 2011 · permalink

Fantastic tool. I’m using it for several months within Firefox.
This is the best REST test plugin I know both on FF and Chrome.

HTML Validator

best firefox add-ons for developers

An icon shows the number of HTML errors on a page.

Add-on User Review:

Must Have Rated 5 out of 5 stars

by Sadie Hebert on August 10, 2012 · permalink

This is a must have add-on for web developers.

Modify Headers

best firefox add-ons for developers

Great for mobile web development. Add, modify, and filter HTTP requests sent to web servers.

Add-on User Review:

Rated 5 out of 5 stars

by Mikef125 on October 25, 2012 · permalink

Excellent piece of work, and ridiculously useful. This saves me a lot of time where I would otherwise have to use a telnet client and manually enter an entire request, or use Fiddler, which is still time-consuming.

Thank-you for getting my butt out of a sling with this.

IE Tab V2

best firefox add-ons for developers

Test your web app or website on IE.

Add-on User Review:

Rated 5 out of 5 stars

by Erwin on May 10, 2012 · permalink

There are many IE Add-on and I’ve tried it. but in my opinion, this is the best IE Add-on. I use it to visit microsoft website and develop my website to see it in IE, without having to open IE browser…

Best Firefox Add-ons – Screenshots

Awesome Screenshot Plus

best firefox add-ons for developers

Capture an entire page, or just a portion, and then annotate it with custom tools.

Add-on User Review:

I recommend it! Rated 5 out of 5 stars

by adriancuervo on January 25, 2013 · permalink

Really useful and well developed. Easy to use, very clear and friendly interface, and stable. You can cut a section or the whole page, annotate, mark and draw and save as jpg or png. Used for a year perfectly.

Pixlr Grabber

best firefox add-ons for developers

Grab, edit, and share images and backgrounds from the web.

Add-on User Review:

Rated 5 out of 5 stars

by Alex N. Dawson on January 14, 2013 · permalink

Amazing plugin for capturing image online. Another plus is that, it has its builtin image editor which has almost the functionality of Photoshop. That means, you have limited functionality of Photoshop in an addon. Very handy.

Since I’ve installed this plugin months ago, I have never experience any issue with it, except for sometimes it slows down…well probably it was caused by internet connection slow down.

Webpage Screenshot

best firefox add-ons for developers

Quickly grab a screenshot of an entire web page and annotate it.

Add-on User Review:

Rated 5 out of 5 stars

by HowToRappel on January 1, 2013 · permalink

Easy to use. Makes nice long image I can use in videos or on my own web projects.

Best Firefox Add-ons – Time-savers and Shortcuts

Speed up your browsing and keep yourself on task with these great Firefox Add-ons.

ColorZilla

best firefox add-ons for developers

Find the HTMl code for any color on any web page.

Add-on User Review:

Rated 5 out of 5 stars

by Alex N. Dawson on January 23, 2013 · permalink

Dealing with colors on the web is difficult if there is no color picker at hand. This extension solved that issue. Whether picking colors for a website design or blending ad colors, it is very helpful

Fire Gestures

best firefox add-ons for developers

Set up mouse gestures for quick shortcuts within your browser.

Add-on User Review:

Rated 5 out of 5 stars

by fr0wn on January 23, 2013 · permalink

Makes browsing a thousand times faster and better.

Video DownloadHelper

Strip almost any video from the web.

Add-on User Review:

Very useful tool! Rated 5 out of 5 stars

by Keanu on February 16, 2013 · permalink

Works without any troubles for me. pretty functional and useful!
DownloadHelper does exactly what its suposed to do. works amazing on tons of sites. also i noticed that developers are responsive and if you will find any bug – they will fix it as soon as possible.
thank you very much

Session Manager

best firefox add-ons for developers

Save and restore any browsing session for later use.

Add-on User Review:

The best sessions manager Rated 5 out of 5 stars

by Max on February 15, 2013 · permalink

Works very well, dev.builds are always available, has a truck load of options, easy to follow documentation with illustrations, change logs, well supported by a very responsive developer (just read the ongoing thread on Mozillazine forum).
Everything one would wish for in an extension.

Multi Links

best firefox add-ons for developers

Open, bookmark, and copy many links at once.

Add-on User Review:

Can’t browse without it Rated 5 out of 5 stars

by leonardofibonacci on February 14, 2012 · permalink

Great addon possibly my most used.

AutoPager

Automatically loads the next page when you reach the bottom of a page with pagination.

Add-on User Review:

Rated 5 out of 5 stars

by firestar001 on January 23, 2013 · permalink

EXCELLENT TOOL MOST USEFUL REDUCING THE STRESS AND EASY FOR BROWSING,THE BEST.

MeasureIt

best firefox add-ons for developers

Draw a box on any page to measure an element’s dimensions.

Add-on User Review:

Rated 5 out of 5 stars

by Alex N. Dawson on January 14, 2013 · permalink

I’m always in need of a measuring tool for editing or customizing my wordpress sites. This addon helps a lot when it comes to measuring padding, width and height. Hopefully, this addon will continuously be udpate for future releases of FF.

TinEye Reverse Image Search

best firefox add-ons for developers

Find an image’s source and see if there are more sizes available.

Add-on User Review:

Absolutely helpful, practically one-of-a-kind Rated 5 out of 5 stars

by nayhem on July 31, 2012 · permalink

Haven’t seen anything like this in … ever. It is very thorough, able to find images that have been edited, resized, cropped, or vary in color. It even finds “meme” versions of images, like (de)motivators, macros, and inserts in comics.

Have a tiny thumbnail? You can probably find a wallpaper version that goes with it, if it’s out there. Produce your own artwork or photos? You can find those [negligent souls] who are using (or selling!) your work without permission.

BlockSite

best firefox add-ons for developers

Keep yourself productive by blocking sites that keep stealing your attention.

Add-on User Review:

Finally, a great URL blocking tool Rated 5 out of 5 stars

by PetrifiedJello on December 18, 2012 · permalink

With Facebook’s invasive cancer in websites all over the place, I needed a way to block the URL (as well as fbcdn) and this little gem is exactly what I was looking for.

Blocking both inbound and outbound URLs, it does the trick for top-level domains.

LastPass

best firefox add-ons for developers

Manage all your passwords in one, secure place.

Add-on User Review:

Rated 5 out of 5 stars

by eUROs on February 15, 2013 · permalink

Since i’ve tried it. I can’t live without it!
Simply the BEST!
FIVE GOLDEN STARS!!

Let us know your thoughts on Chrome vs Firefox for web development use in the comments below!