A Firefox userChrome.css theme that aims to recreate the look and feel of the Chromium version of Microsoft Edge.

  • By null
  • Last update: Jan 2, 2023
  • Comments: 15

Edge-FrFox rewrite

A Firefox userChrome.css theme that aims to recreate the look and feel of the Chromium version of Microsoft Edge.

This branch is for a new version that is rewritten from scratch. Old version can be found here.

The context menu and its icons have not been completed yet.


Screenshot taken with macOS Monterey / Firefox Nightly 96.0a1 (2021-11-30)

How to install

  1. Go to about:support and click the "Show in File Explorer/Finder" button for the root directory of your browser profile/s.

  2. Download and copy the chrome folder into the profile folder.

  3. Go to about:config and change these preferences:

    For all operating systems:
    1. toolkit.legacyUserProfileCustomizations.stylesheets = true
    2. svg.context-properties.content.enabled = true
    3. layout.css.color-mix.enabled = true
    On macOS:
    1. To use the Edge style context menu on macOS then set widget.macos.native-context-menus = false (Not Implemented Yet!)

Note: Most frequently tested on macOS


muckSponge - MaterialFox

Microsoft - Fluent UI System Icons




  • 1

    Horizontal scrolling glitch

    img For some reason, the horizontal scrolling on this theme kicks in too early. On default Firefox, horizontal scrolling starts at ~20 open tabs. On this theme, it already begins way too early at just 7 tabs. There is nothing to scroll anyway, so it takes up unnecessary space. Also, it seems like the "New Tab" animations disappear when this horizontal scrolling glitch occurs. There are no animations at all. For example, this is how it should look like, on default Firefox: img 2

  • 2

    Additional Theme similar to edge

    While using the System-Auto theme, It is indeed replicating Edge's Tab bar color as like in below image:


    But when using Dark theme as below. The Dark theme of Firefox is applied. image

    The second theme is not so good. I want the first tab bar's color when I enable Dark Theme.

    I am suggesting that you create a theme of the first one and list it along other themes if possible or publish a theme in AMO.

  • 3

    New commit is breaking buttons


    As you see in the image, The new commit has breaken things on my fork. I am not sure if this is because of you or my fork.

    And Mica also doesn't apply even though my settings are :


  • 4

    Windows 7 Bug

    Here's a video demonstrating the bug:


    Apologies if the link looks sketchy, videos uploaded to Notion don't have a very pretty URL.

  • 5

    Highlight of address bar matches is too light

    I really like this style. The standard Firefox look is OK, but I think this is better. The icons help provide extra polish.

    Now for my issue...

    When I enter text in the address bar, matching URLs from my history are listed and the first one highlighted. The highlight colour is too light IMO. Can I make this a little darker?

  • 6

    Background images


    Add support for custom background images like in Edge for New tab.

    Note : I am using Background images in my own fork but not in an intuitive GUI way. Maybe you can see it for reference.

  • 7

    Mica for MacOS

    I think Mica/Translucent effect for MacOS can be acheived by using this CSS - https://github.com/zvuc/firefox-macos-native-tabbar

    I would like to make a PR but I have a custom fork for my own customization. So, I don't want to mess it up.

  • 8

    CSS not working

    Description It was working actually, but while I was trying out a firefox modification that adds more functionality, one of them steps to installing it was clearing startup cache which i did but that seem to break the CSS and now I cant get it working again.

    As you can see from the screenshot, custom context menu not working which is suppose to. image


    • Firefox Version: Nightly 107.0a1
    • OS: Windows 10
  • 9

    The Context Menu font could be smaller?

    The Context Menu looks near perfect now with the new edge icons. However, the font is a little larger than how it appears on edge. Could you make the context menu font slightly smaller?

    • Current Font Size:


    • Font Size on Edge:


  • 10

    Improvements to Firefox Badge in Nav Bar


    If you see the video, The Box (Padding) around firefox has blended with the color of the navigation bar. I get the thing that it is similar to edge but edge has a Vertical bar separating the badge and URL.

    Better to fix it.

  • 11

    Explanation for a tweak

    uc.tweak.force-tab-colour - What does this tweak actually do ?

    I am confused by your Wording in Readme. A detailed explanation with images would be great.

  • 12

    Color of alt text for add-ons


    Can you fix the color of the alt text when we hover over the addons or the 3 dot application menu? Currently it shows as a dark shade of purple that FF uses by default.

  • 13

    Hello, using Edge-Fefox In the state of playing video in all video websites, it will make the tab page logo of the video website not display! Hope to solve it!

    Hello, using Edge-Fefox In the state of playing video in all video websites, it will make the tab page logo of the video website not display! Hope to solve it!

    VeryCapture_20230102171727 VeryCapture_20230102171742

  • 14

    PROTIP: Disable Firefox Account Login button and tab in settings


    If you don't using Firefox Account sync - hide buttons and options in settings.

    user_pref("identity.fxaccounts.enabled", false);

    Include screenshot / video recording if possible.

    20221217-1671293466 20221217-1671293449

  • 15

    (NEW) Edge-like search bar

    Description The new Edge search bar is more rounded and feels kinda more soothing :3 Can we have it in the userchrome?

    Include screenshot / video recording if possible. image