FireFox-compact-mode

A minimal, compact Firefox setup that merges the tab bar and nav bar into a single row, with inline URL editing on tabs.

Demo Screenshots

Startup View

New Tab Behavior

Tab Search

Bookmarks Hidden on Load

Features

• Single-row layout — app menu and back button on the left, tabs in the middle, extensions and window controls on the right. No separate nav bar taking up vertical space.
• Inline URL editing — double-click any tab to edit its URL in place, with live autocomplete from your browsing history.
• Smart new tabs — opening a new blank tab drops you straight into the inline URL editor, no address bar needed.
• Typed text stays on the tab — type something in a blank tab's editor and switch away; the text is kept and shown on the tab instead of "New Tab".
• Tabs fill the bar — tabs fill the whole tab bar and split the available width equally.
• Instant tab reflow — closing a tab makes the rest expand immediately (no waiting for the mouse to move away).

Requirements

• Firefox 115+ (tested on Firefox 156)
• fx-autoconfig installed — this is what enables custom user scripts (.uc.js) and the chrome/ folder. Follow its install instructions before proceeding.

Installation

1. Install fx-autoconfig

Follow the instructions at MrOtherGuy/fx-autoconfig. In short:

• Copy config.js and the defaults/ folder into your Firefox install directory (e.g. C:\Program Files\Mozilla Firefox\)
• Copy the chrome/utils/ folder into your Firefox profile folder (find it at about:support → Open Folder next to "Profile Folder")

2. Copy the files from this repo

File in this repo	Copy to
install/channel-prefs.js	<Firefox install dir>/defaults/pref/channel-prefs.js (overwrite)
install/JS/tab-edit-url.uc.js	<Profile folder>/chrome/JS/tab-edit-url.uc.js
install/JS/tab-reflow.uc.js	<Profile folder>/chrome/JS/tab-reflow.uc.js
install/JS/extensions-to-tabbar.uc.js	<Profile folder>/chrome/JS/extensions-to-tabbar.uc.js
install/CSS/tab-fill.uc.css	<Profile folder>/chrome/CSS/tab-fill.uc.css
install/CSS/user-styles.uc.css	<Profile folder>/chrome/CSS/user-styles.uc.css

Create the chrome/, chrome/JS/ and chrome/CSS/ folders inside your profile if they don't exist.

3. Restart Firefox

Fully close Firefox (check Task Manager — no lingering firefox.exe processes) and reopen it. The layout should snap into place and double-clicking a tab should open the inline URL editor.

Usage

• Double-click a tab → edit its URL inline, with history autocomplete.
• Open a new tab → jumps straight into the inline URL editor.
• Arrow keys → navigate autocomplete suggestions.
• Tab → fill the input with the selected suggestion.
• Enter → navigate (URL, domain, or Google search for plain text).
• Esc or click outside → cancel.

Security note

• userChrome scripts run with full browser privileges. They can read all your data and modify anything in Firefox. Only install userChrome scripts from sources you trust, and review them before installing.
• user-styles.uc.css hides the URL bar on normal pages (shown on hover or Ctrl+L). This is a deliberate UI choice, but hiding the address bar is a common phishing trick — be aware of the trade-off.
• tab-edit-url.uc.js only navigates to safe URL schemes (http/https/ftp/about/mailto); javascript:, file:, chrome: etc. are never executed.

Troubleshooting

Scripts aren't loading after a Firefox update. Firefox updates can overwrite defaults/pref/channel-prefs.js, wiping the fx-autoconfig prefs. If your scripts stop working after an update, just re-copy install/channel-prefs.js from this repo and restart Firefox.

Nothing loads at all.

• Make sure Firefox is fully closed before copying files (no firefox.exe in Task Manager).
• Verify chrome/utils/ from fx-autoconfig is in your profile folder, not the install folder.
• Check about:config for xpinstall.signatures.required — if it's false, the prefs loaded correctly.
• Open the Browser Console (Ctrl+Shift+J) and look for red errors.

Layout looks wrong. Your Firefox version might have renamed some toolbar elements. Open an issue with a screenshot.

Files

• install/channel-prefs.js — Firefox prefs that enable fx-autoconfig and legacy customization (userChrome.css, unsigned extensions, experiments).
• install/JS/tab-edit-url.uc.js — Inline tab URL editor with history autocomplete (keeps typed text, hardened URL schemes).
• install/JS/tab-reflow.uc.js — Tabs reflow instantly when one is closed.
• install/JS/extensions-to-tabbar.uc.js — Rearranges app menu, back button, extensions, and window controls into the tab bar.
• install/CSS/tab-fill.uc.css — Tabs fill the whole tab bar and split width equally.
• install/CSS/user-styles.uc.css — Consolidated UI styles (hidden URL bar, tighter toolbar, editor styling).

Credits

Built on top of MrOtherGuy/fx-autoconfig.

License

MIT