Add-ons encompass plug-ins (like Flash, Adobe Reader, and QuickTime) that make existing web tech work, themes for changing a browser's look, and of course, those capability enhancing programs known as extensions that go beyond a developer's dreams.
Of course, you could go your entire browsing life without installing an extension – many people do – but without them, Firefox isn't the web surfing powerhouse it can be.
So, take a look at our selection of the best Firefox extensions and try a few out. They're free, after all. You'll quickly see just how useful they can be...
1. Adblock Plus
What more can we say about an extension that already has more than 14.3 million users? If you hate advertising, you should install this tool and filter the commercials out of your web surfing. The 2.0 version introduced an option to let you view less intrusive ads, thus keeping many of us (ahem) in business. And we thank you.
Almost everyone has an Amazon wish list. It's a great way to let people know just what you want for a special occasion. That list isn't just limited to items available from Amazon, either; with this extension, anything you can shop for online can be added to your wish list for future shopping.
On many websites, you have to slog through page after page to read an entire article. If you're sick of clicking "Next," try AutoPager. It works with a wide variety of popular sites, turning multi-page articles into one long page, automatically loading the next page when you get to the end so the scrolling never stops.
When you're done reading this article, you're going to have a lot of Firefox add-ons installed. This extension makes managing them easier by reducing the size of the page, and making it a snap to disable or remove those you no longer want.
Clearly is a service of Evernote. It takes articles, blog posts, and other web pages that you might be too busy to read and reduces them to just the text you want, distraction-free. You can change the text type and background for optimal readability. Of course, you can then save that same cleaned-up version of the text directly to Evernote for reading later.
Got nothing to hide, huh? Well, just in case you do, install Click&Clean; you'll then find it's a breeze to delete your browser history, download history, cookies, and temp files. It'll make sure that your private data is deleted whenever you close the browser. You can do all of the above and more with one click in the toolbar.
Desktop is a "speed-dial" that lets you add widgets, links, and more to a customised layout on a new tab, providing fast access to your favourite sites and services on the web. Throw in a customised background to really make it your own.
Diigo is a full-blown online service for social bookmarking. With this toolbar installed, you can get the most out of your surfing, using it to annotate pages, highlight text, and keep your bookmarks stored online.
When a web page is filled with downloadable items – be they linked files or just images – why would you download them individually? This extension lets you DownThemAll. You can stop and resume whenever you want.
Evernote is what you need to store things you find online. The service is your personal online database of clips, links, or entire pages of data to reference later. Web Clipper saves them in the background while you keep surfing, and syncs with the desktop and mobile versions so you can access the info anywhere, at any time.
Not to be confused with FasterFox, which makes performance tweaks, this is FastestFox. It enhances your web browsing experience by giving you a quick pop-up menu (the qLauncher) for fast access to searches, price comparisons, Wikipedia searches, and more that you can customise. You'll be hitting Ctrl+Space to click on items all the time.
The Firefox Environment Backup Extension is all about backing up the whole browser environment – hence the name. It copies bookmarks, profiles, preferences, cookies, themes, and extensions to a safe place. You can back up or restore just the parts you want.
The RSS readers on phones and tablets are all about making the experience of feed-reading more pleasant. Feedly does that in Firefox (and other browsers), turning your RSS into magazine-esque readable bites. You'll need a Google Reader account to use it, and Twitter to share what you like.
Need to access a server somewhere with full-fledged FTP but don't want to exit your browser? You don't have to with FireFTP. It loads the app in a tab and gives you everything you need without having to access a separate program. It works with Firefox on Mac, Windows, and Linux, too.
Why access your favourite social network or microblog platform with a bookmark, when you can post and receive full updates with a click in a toolbar? FireStatus works with Facebook, Twitter, FriendFeed, and others.
It's no secret that Adobe's Flash is no longer the darling of web development, but if you hate Flash animations and applications with a passion, try Flashblock to obliterate them. Why not just uninstall Flash? Because sometimes you need access; Flashblock's placeholder images give you the option to click and open the content, if necessary.
Wondering who's tracking your every move as you surf? Ghostery keeps you up to date by detecting all the "invisible" parts of a web page (such as web bugs) so you can see who's doing what. You can then opt out of tracking by letting Ghostery's GhostRank sit in-between you and them.
This one is for Gmail users only, but it makes a huge difference to that web-based email's interface. Gmelius removes ads, the chat, and other widgets. It links the Gmail logo to your inbox, and offers a number of other minor enhancements.
One of the most versatile add-ons ever, Greasemonkey uses scripts downloaded at userscripts.org to further customise web pages. Sometimes it customises every page you encounter; other times scripts are specific to a certain website. You can write your own scripts, too. To get them working, Greasemonkey has to be there.
20. Image Preview
What Image Preview does is pretty simple; if you move your mouse over an image on a web page in Firefox, it will pop-up a preview window of the picture (if it links to a larger version of itself in JPG, GIF, PNG, or BMP formats).
LastPass is an excellent option when it comes to encrypting and keeping your password for safe-but-easily-accessible use. Considering the number of sites that require username and password credentials, it's inexcusable not to have this installed to keep you secure. Use it on any platform (mobile or desktop), and you should also install it with IE and Chrome if you use those as well.
There's nothing worse than having filled out a form on a website and then losing all the info in a browser crash or site reload. Lazarus saves it all as you go, so you never have to retype it again.
Google Chrome's "omnibox" address bar is both the place to type searches and URLs when you want to visit a site. Firefox separates the address from the search – until you install Omnibar and combine their strength in one. It also supports wildcards and auto-complete.
24. Open in Chrome
Most people install multiple browsers on a PC, just in case. If you're still a Firefox aficionado but want to try some of the action in Chrome, this extension will instantly send the tab you're in (or all the tabs you have open) to Google Chrome.
Facebook, Google+, Twitter, and other social networks like to know what you're up to. They also like to know what you like; why else provide all those "+1" and "Like" buttons? Priv3 lets you stay logged in to those social networks, but will prevent them from knowing what other sites you surf.
26. Site to Phone
Sometimes porting favourite sites from your desktop browser to your mobile browser is a pain. Site to Phone minimises any fuss, allowing you to send links that will work every time to iOS, Android, WebOS, Windows Phone, or BlackBerry phones. This one works in every browser, with extensions for IE and Chrome, too.
Stylish is similar to Greasemonkey (number 20) in that it changes how sites function via user-created scripts, but Stylish focuses on fashion; it modifies the actual theme of the site. You can find user-created styles at userstyles.org.
28. Tab Mix Plus
Take total control of your Firefox tabs with Tab Mix Plus, which provides shortcuts and extras you never imagined. Quickly reopen closed tabs, duplicate tabs, and control a full tab session manager that recovers tabs even after a crash.
Why should you have to cut and paste items you like into Twitter? With Tweetlight, just highlight and hit Ctrl+Shift+E (or use a context menu) to share your selections instantly with followers.
If you think that videos on sites like YouTube can only be viewed online, think again. This extension works with hundreds of similar sites to grab video or audio for your future viewing pleasure anywhere.
Reputations should be earned, even online. The Web of Trust (WOT) is an online community of like-minded users rating websites for trustworthiness. You can use the WOT extension to learn what sites are safe when it comes to privacy, child safety, and vendor-reliability based on ratings given by others. You should add your own ratings as you go to further the Web of Trust.
No collection of browser add-ons is complete without Xmarks. Whether you use Firefox, Chrome, Safari, or IE, this service makes sure your browsers all have the same synced bookmarks and passwords.
Stay in touch with everyone and anyone on your social networks with Yoono. Via columns of data, you can see streams from Facebook, Twitter, LinkedIn, YouTube, and your IM services. The combos are almost endless. Yoono comes in desktop and mobile apps, but might be strongest as a browser extension (for Firefox and Chrome) across all operating systems.
It's all about sources at Zotero. This digital research assistant helps you collect and manage sources you want to cite or track. It stores PDFs, notes, and entire pages (in case you think the data might change). You can sync your data at Zotero.org so it's never lost, and you can integrate the info with office suite software. This plug-in can even run as a standalone Zotero app for Windows, Mac or Linux.
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