Hidden/Advanced Preferences

A list of useful flags in Zen Browser's Advanced Preferences page (about:config).

These are a variety of settings that can change Zen's appearance, behavior, and more. To access them, go to about:config in Zen Browser, and search for the title of the flag. Some of these flags may require a restart to work.

Appearance

`zen.theme.content-element-separation`

Changes the size of the border around the browser window. 8 by default.

`zen.theme.accent-color`

The color hex value of Zen's main accent color.

`zen.theme.essentials-favicon-bg`

Enables a colorful icon for when an essential tab is selected, based on the website's favicon. Enabled by default.

`zen.theme.gradient`

Allows setting custom sidebar colors. Enabled by default.

`zen.theme.gradient.show-custom-colors`

Allows setting a color hex as your sidebar color. Disabled by default.

`zen.view.experimental-rounded-view`

??? Disabled by default.

`zen.view.gray-out-inactive-windows`

If a window is inactive, the theme color fades to gray. Enabled by default.

`zen.watermark.enabled`

Shows a splash screen briefly when Zen is opened. Enabled by default.

Transparency & Blur

`zen.theme.acrylic-elements`

Windows-specific. Allows use of Windows' Acrylic protocol for a blur effect in Zen. Enabled by default on Windows.

`zen.widget.linux.transparency`

Linux-specific. Makes the browser UI transparent.

`browser.tabs.allow_transparent_browser`

Changes the default website background to your theme color. Disabled by default.

Enabling could break the way certain websites look.

Tabs

`zen.tab-unloader.excluded-urls`

A comma-separated list of URLs exempt from being unloaded.

`zen.tabs.dim-pending`

Dims unloaded tabs. Enabled by default.

`zen.tabs.rename-tabs`

Allows renaming pinned tabs. Enabled by default.

`zen.ctrlTab.show-pending-tabs`

Allow switching to unloaded tabs using Ctrl+Tab, when "Ctrl+Tab cycles through tabs in recently used order" is enabled. Disabled by default.

`zen.startup.smooth-scroll-in-tabs`

Turns on smooth scrolling when scrolling through tabs. Enabled by default.

`toolkit.tabbox.switchByScrolling`

Allows to switch tabs by scrolling when hovering over tabs. Disabled by default.

New Tabs

`zen.urlbar.replace-newtab`

Replaces opening a new tab, with instead showing the URL bar and allowing you to input a query which will then open a new tab. Enabled by default.

`zen.workspaces.open-new-tab-if-last-unpinned-tab-is-closed`

Opens a new tab when all pinned tabs are unloaded, and all tabs are closed. Disabled by default.

URL Bar

`zen.urlbar.hide-one-offs`

Hides the alternative search engines from appearing in the URL bar. Enabled by default.

`zen.urlbar.show-domain-only-in-sidebar`

When Single Toolbar is enabled, shows only the website domain(ex: example.com) instead of the full URL(ex: example.com/page). Enabled by default.

`zen.urlbar.show-protections-icon`

Shows the "protections" icon in the URL bar, which details security information about the current website. Disabled by default.

`zen.urlbar.wait-to-clear`

How long the URL bar saves what you typed, if you typed something in and unfocused it in milliseconds. 45000 by default.

`zen.view.sidebar-collapsed.hide-mute-button`

Hides the mute button in Collapsed Toolbar mode.

`zen.view.sidebar-expanded.max-width`

Controls the width of the sidebar in Single Toolbar or Multiple Toolbars mode.

`zen.view.sidebar-height-throttle`

??? 200 by default.

Window Controls

`zen.view.hide-window-controls`

Hides the window controls. Enabled by default.

In Single Toolbar mode, this hides the toolbar, which can then be revealed on hover.

`zen.view.experimental-force-window-controls-left`

Forces the window controls to appear on the left side of the window. Disabled by default.

If the sidebar is in the left side, it will appear in it.

`zen.view.experimental-no-window-controls`

Removes the window controls entirely. Disabled by default.

This will disable the toolbar in Single Toolbar mode.

Workspaces

`zen.workspaces.swipe-actions`

Allows swiping with the trackpad on the sidebar to switch workspaces. Enabled by default.

When swiping through tabs, allow going to the last workspace from the first workspace by swiping left, or vice versa. Enabled by default.

`zen.workspaces.natural-scroll`

Turns on natural scrolling for swiping through workspaces. Disabled by default.

`zen.workspaces.scroll-modifier-key`

Controls the hotkey that enables hovering over the sidebar and switching workspaces by scrolling. Options are 'ctrl', 'alt', 'shift'. Default is 'ctrl'.

Compact mode

Animates the webpage moving in/out when compact mode is enabled/disabled. Enabled by default.

Colors the sidebar with your custom theme color during compact mode. Enabled by default.

Colors the toolbar with your custom theme color during compact mode. Enabled by default.

`zen.view.show-background-tab-toast`

Shows a toast when a tab is open while compact mode is enabled. Enabled by default.

Shows the sidebar/toolbar if you hover in their general area during compact mode. Enabled by default.

Shows the sidebar for a moment when opening a new tab during compact mode. Disabled by default.

zen.view.compact.toolbar-flash-popup.duration controls the duration in milliseconds. 800 by default.

Hidden/Advanced Preferences

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