• Firefox 115
• Windows
• MacOS
• Linux

• Download the chrome folder and put it in your user profile folder. For convenience, use about:profiles

• Go to about:config and activate the keys below

  • toolkit.legacyUserProfileCustomizations.stylesheets
  • layout.css.has-selector.enabled
  • svg.context-properties.content.enabled (Activate this key if the menu icons don't follow the general design color. Previously seen only on MacOS)

• Specify the desired shape of the tabs.

  Creation of keys

  Restart your browser for the changes to take effect.

  

  Tabs (Option 1)

  

  • userChrome.Tabs.Option1.Enabled

  Tabs (Option 2)

  

  • userChrome.Tabs.Option2.Enabled

  Tabs (Option 3)

  

  • userChrome.Tabs.Option3.Enabled

  Tabs (Option 4)

  

  • userChrome.Tabs.Option4.Enabled

  Tabs (Option 5)

  

  • userChrome.Tabs.Option5.Enabled

  Tabs (Option 6)

  

  • userChrome.Tabs.Option6.Enabled

  Tabs (Option 7)

  

  • userChrome.Tabs.Option7.Enabled

  Tabs (Option 8)

  

  • userChrome.Tabs.Option8.Enabled

  Tabs (Option 9)

  

  • userChrome.Tabs.Option9.Enabled

  Tabs (Option 10)

  

  • userChrome.Tabs.Option10.Enabled

  Tabs (Option 11)

  

  • userChrome.Tabs.Option11.Enabled

  Tabs (Option 12)

  

  • userChrome.Tabs.Option12.Enabled

Works with modern versions of Windows 11 / Windows 10. System effects must be supported on the operating system side. Otherwise, you need third-party software, such as Mica For Everyone. You also need to disable the accent color in the operating system settings, if it was enabled. Works only with the system theme.

Download and install Mica For Everyone from here.

• userChrome.Windows.SystemEffects.Enabled

Works only with the system theme.

• userChrome.Toolbar.Transparency.Low.Enabled
• userChrome.Toolbar.Transparency.Medium.Enabled
• userChrome.Toolbar.Transparency.High.Enabled
• userChrome.Toolbar.Transparency.VeryHigh.Enabled

Requires Linux with transparency support. Tested on Linux Manjaro KDE + ForceBlur. Transparency is active for all modes, but does not work everywhere. This may change with future browser updates. Works only with the system theme.

• userChrome.Linux.Transparency.Enabled
• gfx.webrender.all (Required key)

The tab frame consists of type, color and saturation. Not compatible with themes that use a translucent toolbar.

• userChrome.LightTheme.TabFrameType.Border.Enabled
• userChrome.LightTheme.TabFrameType.Shadow.Enabled

• userChrome.LightTheme.TabFrameColor.Auto.Enabled
• userChrome.LightTheme.TabFrameColor.White.Enabled
• userChrome.LightTheme.TabFrameColor.Black.Enabled

• userChrome.LightTheme.TabFrameSaturation.Low.Enabled
• userChrome.LightTheme.TabFrameSaturation.Medium.Enabled
• userChrome.LightTheme.TabFrameSaturation.High.Enabled
• userChrome.LightTheme.TabFrameSaturation.VeryHigh.Enabled

• userChrome.DarkTheme.TabFrameType.Border.Enabled
• userChrome.DarkTheme.TabFrameType.Shadow.Enabled

• userChrome.DarkTheme.TabFrameColor.Auto.Enabled
• userChrome.DarkTheme.TabFrameColor.White.Enabled
• userChrome.DarkTheme.TabFrameColor.Black.Enabled

• userChrome.DarkTheme.TabFrameSaturation.Low.Enabled
• userChrome.DarkTheme.TabFrameSaturation.Medium.Enabled
• userChrome.DarkTheme.TabFrameSaturation.High.Enabled
• userChrome.DarkTheme.TabFrameSaturation.VeryHigh.Enabled

• userChrome.TabSeparatorsLowSaturation-Enabled
• userChrome.TabSeparatorsMediumSaturation-Enabled

By default context menus follow the selected interface density, but it is possible to set a fixed size.

Compact	Normal	Touch

• userChrome.CompactContextMenu-Enabled
• userChrome.NormalContextMenu-Enabled
• userChrome.TouchContextMenu-Enabled

Regular	Filled

• userChrome.RegularMenuIcons-Enabled
• userChrome.FilledMenuIcons-Enabled

• userChrome.DragSpace.Left.Disabled
• userChrome.DragSpace.Right.Disabled
• userChrome.DragSpace.Top.Windowed.Enabled
• userChrome.DragSpace.Top.Maximized.Enabled
• userChrome.DragSpace.Top.Fullscreen.Enabled

• userChrome.PinnedTabsWidthLowIncrease-Enabled
• userChrome.PinnedTabsWidthHighIncrease-Enabled

• userChrome.Tabs.SelectedTabIndicator.Enabled

• userChrome.OneLine.TabBarFirst.Enabled
• userChrome.OneLine.NavBarFirst.Enabled
• browser.tabs.inTitlebar (Enable this key if there are problems with window control buttons. Set the value to 0)

Low values are more suitable for high resolution monitors.

• userChrome.OneLine.NavBarWidth.Low.Enabled
• userChrome.OneLine.NavBarWidth.Medium.Enabled
• userChrome.OneLine.NavBarWidth.High.Enabled

• userChrome.TabsOnBottom-Enabled
• browser.tabs.inTitlebar (Required key. Set the value to 0)