Goodbye sore eyes
Hello dark theme for FireFox ®

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An open source project developed and maintained by Pat Johnson.

A universal dark theme — compatible with Firefox 57+

ShadowFox was inspired by changes made in Firefox 57, which limited the amount addons could customize both the user interface and "protected" web pages.
This project aims at creating a universal dark theme for Firefox while adhering to the modern design principles set by Mozilla.

Quick installation

Our cross platform installer takes the guess work out of installation. With a few clicks of a button, ShadowFox can be downloaded or seemlesly updated without losing custom configurations.

Complete theme

ShadowFox is the most complete theme available, styling not just the entire user interface, but also "protected" webpages that aren't accessible to normal extensions, like about:preferences and about:addons.

Addon styles

Addons are one of the hallmarks of Firefox. Unlike any other theme, ShadowFox has custom styles available for the most popular extensions, like uBlock Origin, uMatrix, ViolentMonkey, Decentraleyes, Stylus and so many more.

Easy to customize

We don't limit your creativity, which means you can customize the colors used and add as many custom tweaks as you want. The possibilities are endless!

How it works


Activate the default dark theme Firefox provides (which only alters the navigation and tab bar).


Download the updater script for your operating system.


Run the script and select your Firefox profile and whether or not extensions should be styled.


Make customizations until your heart is content (make sure to run the updater again if you do).


Restart Firefox.


Enjoy your new dark theme, your eyes will thank you!

Users have great things to say

ShadowFox has relieved a lot of strain on my eyes, thank you for the project it really helps.
Thanks for all the hard work man. Mozilla should add this project to Firefox honestly. Cheers.
Just discovered this and wanted to say THANK YOU for this awesome project, I love it!
What a great project! Thank you so much for that awesome work!
Just wanna say thanks for bringing my favorite theme back!
This should officially be merged

Download Today

A cross-platform installer/uninstaller/updater is maintained in the shadowfox-updater repository.

Latest versions can be obtained via the links below, through the releases page, Homebrew, or AUR. Please see the README file for details on how to use the updater (GUI and CLI options available) and solutions to common problems.


This section can be used to customize the colors utilized by ShadowFox. Accent colors are used for things like buttons, links and tables. The drop down box can be used to darken ShadowFox by one shade. Only necessary changes are inserted into the text box. For more information, see here.

The following tweaks are not written or maintained by me. Instead, they are pulled from popular userChrome repositories from across the web. The location of the tweak along with the appropriate license is attached with each code chunk.

Find a bug? Have a feature request? Have any questions?

Please first read through the GitHub Wiki , which includes more detailed instructions and information, and take a look at any open issues . If you can't find a duplicate request, bug, or an answer to your question, please feel free to either:

• Open a new GitHub issue.
• Make a post on the ShadowFox subreddit.
• Message me on Slack.