This article is continually updated to reflect the most recently available Firefox add-ons. More of a Chrome user? Check out our list of the best Google Chrome extensions.
Firefox is one of the most popular browsers on the market, and although it wasn’t the first Web browser to support extensions, it definitely has the largest library of them. Third party developers have been making custom Firefox add-ons for years now, and with a library that numbers in the millions, it can be hard to track down the best ones. For that reason, we’ve put together this list of our favorites that are sure to give your browser a boost.
The end-all be-all of browser extensions. This one lets you run countless custom user-created scripts and tweak the Internet in tons of different ways.
We hate to break it to you, but your browsing isn’t private. On almost every website you visit, bugs and trackers collect data on the pages you go to and the links you click. Ghostery blocks over 1,000 of these bugs and provides you quick access to more information about the ones it’s blocking
AutoPager eliminates the need for you to click “next page” ever again. The extension auto-loads subsequent pages on any multi-page site and allows you to scroll continuously through the contents.
Much like you’d expect, this one makes Firefox faster. We’re not exactly sure how it works, but we do know that it does.
Have an image and need to find it in a different size or format? Use TinEye to track it down, and also search for similar images.
With a namesake from the man whom Jesus brought back to life four days after he was dead, the Lazarus extension more or less does what its biblical lore describes: it recovers everything you enter into form fields. So, if the page crashes or times out, you don’t lose everything.
Highlight any text in a foreign language, right-click on it, and you’ll instantly be given a Google-powered translation into the language of your choice.
Lastpass saves all your passwords in a locally encrypted vault, so not even LastPass has access to them. In addition to saving and auto-filling passwords, it can also be used to generate highly secure passwords when you create new accounts.
This extension is a project from the Electronic Frontier Foundation, and pretty much does what it sounds like it does. It encrypts your communications with major websites, turning the site from “http” to “https,” ensuring that your browsing is secure.
TrackMeNot is a lot like Ghostery in that it seeks to keep your browsing habits private. However, it takes an entirely different approach. Rather than blocking bugs and trackers, TrackMeNot obfuscates your browsing by sending out randomized queries every so often.
This add-on allows you to remove or manage locally shared objects (LSO’s) – better known as Flash cookies.
Web of Trust is a user-ratings-based add-on that informs you about the level of security behind a link before you click on it. It has a user base of over 1.6 million users (and more on Chrome), so the trustworthiness ratings are generally pretty reliable.
FEBE, which stands for Firefox Environment Backup Extension, backs up all of your add-ons by building installable .xpi files and saving them locally on your computer.
This is a shopping helper extension that works by indexing thousands of shopping sites and alerting you if there’s a lower price for any item you’re looking at.
Nobody likes getting all squinty-eyed trying to see what thumbnail pictures are. With this extension, thumbnails will be enlarged when you hover over them with your mouse
This one is somewhat similar to Thumbnail Zoom and Image Zoom, but it works for image links. Hover over the hyperlink of any image and this add-on will give you a preview of the picture.
Similar to Thumbnail Zoom, this add-on enlarges images on the Web to their full size when you hover over them with your mouse. It doesn’t work with every image you’ll come across, but it works with most of them.
This handy little add-on will tell you why the page you’re on is running so slowly. It uses Yahoo’s rules for high-performance Web pages and suggests ways to improve the performance of the page you’re viewing.
This one is pretty self-explanatory: you can quickly send whatever you’re looking at in your desktop browser directly to your phone
A must-have for students, this extension manages all of your sources while you’re doing research and provides simple tools to help you create citations.
This handy add-on blocks all ads on the Web and leaves you with nothing but plain ol’ websites.
WindowShopper makes shopping online a more visual experience. Instead of searching with text, it allows you to use image searches to find products similar to the one you’re viewing.
This one allows you to execute various commands with mouse gestures, rocker navigation, scroll-wheel navigation, and page scrolling.
Love Chrome’s Omnibar, but don’t want to betray your beloved Firefox? Don’t worry, this add-on will give your search bar all the same functionality.
Most of the time when you’re copying text, you want the text, but don’t need the formatting that comes along with it. Copy Plain Text allows you to copy stuff to your clipboard sans formatting.
NSA’s broad scale domestic spying program, you’ve got more reason than ever to encrypt your online communication. CryptoCat is a secure chat client that uses the OTR protocol and AES-265 encryption to keep your messages secure.
Hate all the ignorance and prejudice you find in YouTube comments? Hide it all from your eyes with Herp Derp, an extension that transforms all comments on YouTube into a random string of herps and derps.
Found an awesome article online, but don’t have time to read the whole thing? Use this extension to send it to Pocket, arguably one of the best read-it-later apps on the market.
Ever wanted to download a YouTube video? There are dozens of sites that’ll get the job done, but none can compare to ClipConverter’s speed, versatility, and ease of use. This extension basically provides a set of buttons that let you download the video as an MP3, MP4, or virtually any other major file format.
Did we miss any of your favorites? Tell us about them in the comments section below!