Mozilla Firefox is easily one of the most popular open-source web browsers among Linux users.
In fact, it is one of the best web browsers available for Linux. But, what about its add-ons (or extensions)?
Considering that you prefer open-source solutions, are you using add-ons for open-source services? What are some of the best open-source Mozilla Firefox add-ons that you can install?
Open-Source Mozilla Firefox Extensions You Should Try
It is important to note that just because it’s Firefox, not every add-on is open-source.
Furthermore, there are several open-source projects with a Firefox add-on, but with a different license.
1. Dark Reader
Dark Reader is a popular browser extension that lets you turn on the dark mode for websites. The extension simply changes the background and text color to blend in as a dark mode theme.
By default, it works well with almost every website. However, if you think that a dark mode is unreadable (or doesn’t look good), you can customize the color, contrast, brightness, and grayscale as well.
You can also choose to enable it on specific websites and have it disabled for the rest. In either case, you can create a list of sites to whitelist/blacklist.
It is an open-source project that respects users’ privacy. You can explore more about it in its GitHub page or get the add-on to try it out.
Undoubtedly, one of the best password managers available out there.
Bitwarden is an open-source password manager offering a variety of features. It focuses on providing competitive open-source solutions.
The password manager add-on available for Mozilla Firefox is no less than any other similar offerings. You get all the essential functionalities starting from generating passwords, managing your vault, along with some advanced options right through the extension.
In my use case, I don’t find the extension lacking anything at all. And, you should try the add-on if you haven’t already. You can take a look at its GitHub page to explore more.
An open-source tool inspired by Vim keyboard shortcuts, originally popular for Chrome, ported to Firefox.
The add-on is a work in progress for Mozilla Firefox, with no recent activity. However, as an experimental add-on, it still has excellent user reviews.
This add-on lets you use keyboard shortcuts to improve your browsing experience. For instance, you can set shortcuts to scroll, view source code, enable insert mode, browse the history, check downloads, and more.
If you are comfortable with keyboard shortcuts, this add-on should be on top of your bucket lists to try if you haven’t.
You can find its GitHub page and explore several customized versions (forks) of it as well.
4. uBlock Origin
If you want to get rid of several dynamic elements in a website to improve the browsing experience, uBlock Origin is a fantastic content blocker for the job.
For starters, it blocks a wide range of ads, trackers, pop-ups, to make the web page faster to load. It should come in handy if some web pages stutter when it loads up in your browser.
Advance features like blocking malicious domains, blocking media bigger than a specific size, should help you stay secure and save internet bandwidth. Explore its GitHub page for more technical details.
Note: For this list, we try to recommend Firefox add-ons that are totally open-source. But, this is an exception as a non-foss add-on, where the service is originally open-source, but the extension is not.
LanguageTool is an open-source grammar and spellchecker that respects your privacy, making it a decent alternative to the likes of Grammarly and others. It is free to use, with an optional premium upgrade for advanced correction features.
It should be good enough for basic spellcheck and common grammatical mistakes. As I write this, I have LanguageTool Firefox extension active. Not just a privacy-focused, open-source alternative, it works super quickly without impacting your writing experience.
The server-side is open-source but unfortunately, the add-on is not open-source. They clarified the reason as they do not want competitors to use the add-on and contribute nothing in return (more in their forum post).
If you want the convenience of managing multiple tabs with different active windows, Tabby should come in handy.
It simplifies the method of managing several tabs and windows of a browser and also lets you save tabs/windows to use later. When it comes to tab management, Firefox isn’t a champion, so you might want to try this out.
You can check out its GitHub page to explore more, or get the add-on below.
It isn’t easy to pick or use an emoji using the desktop. With this open-source extension, you get access to several emojis that can be easily copied to the clipboard with a single click.
The add-on is entirely open-source and also uses some open-source fonts with the add-on.
You can find more about it on its GitHub page.
DownThemAll is a powerful add-on to easily download multiple files/media from a webpage. You can choose to download everything in a single click or customize the ones you want.
There are some extra options to customize the file name, queue-based downloads, and advanced selection.
9. Tomato Clock
If you want a Pomodoro functionality in your web browser (like Vivaldi offers out-of-the-box), Tomato Clock is the add-on you need.
In other words, it lets you set timers to help you break down your work in intervals with short breaks in between. This should help you stay productive without getting overwhelmed with work.
It is simple to use and also shows you some usage stats to see how well you make use of it.
You can explore its GitHub page for technical info or get the extension to start.
While there are several other useful Firefox add-ons available, I limited the list to the best ones I found myself using.
What are some of your favorite open-source Firefox add-ons? Let me know in the comments down below.