Recommended Extensions
These are the add-ons most often recommended by the social Firefox community, with a focus on add-ons that don’t cause problems.
You can find Mozilla’s recommended add-ons on AMO.
Add-ons by purpose
Ad blocking
SponsorBlock (⭐ Open Source 🏆 Recommended by Mozilla) will skip over sponsored segments, intros and more in YouTube videos.
Privacy and Security
uBlock Origin (⭐ Open Source 🏆 Recommended by Mozilla) The best ad and tracker blocker. Do not use other ad blockers with the same filter lists (e.g. AdBlock Plus or Adblock) alongside this add-on, things will break.
Dark Mode
Dark Background and Light Text (⭐ Open Source 🏆 Recommended by Mozilla) A simple extension which makes website backgrounds black and text white. Although it doesn’t look as nice as Dark Reader, it offers much better performance.
Dark Reader (⭐ Open Source 🏆 Recommended by Mozilla) changes every website to light text on a dark background. Makes complicated changes to website color schemes so that it looks natural.
Midnight Lizard (🏆 Recommended by Mozilla) custom color schemes for all websites: night mode, dark themes, blue light filter, screen shader, high contrast, grayscale, etc.
Container Add-ons
Multi-Account Containers (⭐ Open Source 🏆 Recommended by Mozilla) allows for the easy creation of containers and can force a website to always open in a container. Made by Mozilla.
Facebook Container (⭐ Open Source 🏆 Recommended by Mozilla) isolated Facebook from the rest of the internet. Made by Mozilla.
Google Container (⭐ Open Source) fork of Facebook Container for Google websites.
Temporary Containers (⭐ Open Source) allows the easy creation of throw-away containers isolated from the rest of your tabs.
Website Enhancers / Changers
Old Reddit Redirect (⭐ Open Source) redirects reddit.com to old.reddit.com.
Reddit Enhancement Suite (⭐ Open Source) adds additional features and customisability to reddit.
Youtube
Enhancer for Youtube (🏆 Recommended by Mozilla) adds more functionality and enhancements to YouTube.
Add-ons to replace features you may be used to
In page translation
Many Chrome users miss the Google translate feature built into Chrome that automatically detects a foreign language web page and offers to translate it. There are decent translation add-ons available for Firefox.
Firefox Translate (⭐ Open Source) Translate the web without the cloud.
Page Translator Revised (⭐ Open Source) This add-on allows you to choose between Microsoft Translator and Google Translate, and you can also automatically translate pages once you visit a foreign language page. When translating pages, the translated page opens in a new tab.
Translate Web Pages (⭐ Open Source) This add-on allows you to choose between Yandex and Google Translate. You can also automatically translate pages once you visit a foreign language page, and the extension can also translate selected text on pages.
Set Tabs Aside
Microsoft Edge had a set tabs aside feature that made it easy to hide tabs and have a clean window to help you focus. You can use Set Aside Tabs to get this feature in Firefox.
Search Google for image
If you miss being able to search by image, there are many add-ons that can help you. Here are two that allow you to search by image:
Search by Image This add-on has many built in engines, and many options. The interface may be a bit heavyweight for some (it adds a toolbar icon, but that can be removed in Firefox). If you enable more than one engine, they appear in a sub-menu, and you can open them all at once in the background if you prefer.
Reverse Image Search Very similar to the one above, except that it allows you to add your own engines. If you enable more than one engine, they appear in a sub-menu, and you can open them all at once in the background if you prefer.
Image Search Options Set of highly customizable reverse image search context menu options.
Sync bookmarks with Chromium browsers
A lot of people want to switch over, but they may want to keep their bookmarks in sync, in case they want to use a Chromium browser for certain sites or on occasion.
xBrowserSync is a cross browser extension for Firefox and Chrome. It is encrypted end to end and doesn’t require a sign up.
Paste and Go
Vivaldi users may miss the Control+Shift+v shortcut to paste and go to a URL. Paste and Go Key brings this feature to Firefox.
Paste and Go in built right into the address bar as a right-click mechanism.
Hover Zoom
The Firefox version of this popular enlarge on hover extension has issue. Imagus is a good alternative.