Built-in "Auto-hide toolbars" option (like Vivaldi's UI Auto-hide)

[ericperuzzo]

The problem
Firefox only auto-hides its toolbars in full-screen mode, which also hides the OS taskbar and the window controls. If you just want the maximum page area in a normal window, there is no supported way to get it. Extensions can't touch the browser UI, and the userChrome.css workaround needs an about:config pref and can break between releases.

Why it matters now
With vertical tabs, the only top toolbar left is the address bar. Hiding it frees a full row of vertical space on every page, which helps most on laptops and wide, short screens.

Prior art
Vivaldi's "UI Auto-hide" (Settings → Appearance) hides the interface, or any selection of toolbars, until the pointer reaches a window edge. It can also be limited to full screen.

Proposal
Add an "Auto-hide toolbars" option under Browser Layout:

• Choose which toolbars hide (address bar, tab strip when horizontal, bookmarks bar).
• Reveal when the pointer touches the top edge, overlaying the page without resizing it.
• Keep the toolbar open while the URL bar is focused or a menu or panel is open.
• Optionally apply it only in full screen, without hiding the taskbar.

Working prototype
I built this as a small userChrome.css, tested on Firefox 157 on Linux (Flatpak) with vertical tabs. It includes a short demo GIF, an installer, and a prototype extension with a settings page:
https://github.com/ericperuzzo/firefox-ui-autohide

It is only a stopgap. The extension needs an Experiment API, so it can't be published on addons.mozilla.org. A native option would make this available to everyone.

[kelimuttu]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[kelimuttu]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.