Live Editing Zen Theme

This guide will help you customize the appearance of Zen Browser by live editing the userChrome.css file. Follow the steps below to start customizing your browser’s theme.

Step 1: Access the Profile Folder

1. Open Zen Browser.
2. Type about:support in the address bar and press Enter.
3. Look for the Application Basics section.
4. Click on Open Profile Folder. This will open the folder where Zen Browser stores your user data.

Warning

On the flatpak version of Zen, the profile folder will be located at ~/.var/app/io.github.zen_browser.zen/.zen.

Step 2: Create the chrome Folder

1. In the Profile Folder, create a new folder and name it chrome.
2. Inside the chrome folder, create a new blank file named userChrome.css.

Step 3: Open Style Editor in Zen Browser

1. In Zen Browser, press Ctrl + Shift + Alt + I to open the Developer Tools.
2. Navigate to the Style Editor tab.
3. In the filter/search bar, type userChrome to locate the userChrome.css file you created earlier.

How do I enable the Browser Developer Tools?

After Zen Browser version 1.0.0-a.31 the Browser Developer Tools is disabled by default for security.

1. Open the about:config page. This page contains advanced settings for the browser.
2. Search for devtools.debugger.remote-enabled
3. Toggle the setting to true by double-clicking on it

Step 4: Edit the userChrome.css File

1. The userChrome.css file should now be visible in the Style Editor.
2. You can start editing the file directly within the Style Editor.
   • Note: You can use the Inspect button to hover over and select elements on the page. This allows you to learn about the id, class, or other attributes of elements, which you can then target in your userChrome.css file.
3. To apply your changes, save the file by clicking Save or by pressing Ctrl + S.

Warning

If a style does not apply as expected, try adding the !important keyword at the end of the CSS rule. This forces the browser to apply the style regardless of any other existing styles.

Tip

If you wish to edit pop-ups or menus that automatically hide, be sure to enable the Disable Popup Auto-Hide option from the Browser Toolbox settings menu ( ⋯ button )

Any changes you make to the userChrome.css file will be applied immediately to Zen Browser. Use this file to customize various UI elements, such as colors, fonts, and the layout.

You can use this guide to help you create your Zen theme and publish it.

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This guide is designed to help you quickly and efficiently customize your Zen Browser experience. Happy theming!