Firefox Tab Compactor

This is an extension that uses userChrome.css to allow tabs to significantly decrease in size in the toolbar.

I also recommend setting browser.compactmode.show to true in about:config and going into more tools > customize toolbar and setting the mode to compact for more space savings.

Installation

This can be installed as a theme or as a userChrome.css file.

UserChrome.css

To use this as a userChrome.css file, follow these steps:

1. Open Firefox's about:config page.
2. Find the toolkit.legacyUserProfileCustomizations.stylesheets preference and set it to true.
3. Create a new folder in your Firefox profile directory called chrome.
4. Inside the chrome folder, create a new file called userChrome.css.
5. Paste the contents of userChrome.css into this file.
6. Restart Firefox.

Theme

To use this as a theme, follow these steps:

1. Be using a Nightly or Developer build of Firefox.
2. Follow the building extension instructions to create the extension zip file.
3. Set the about:config Options Required for Testing Theme.
4. Open Firefox's about:addons page and drag the zip file onto the page to install the theme.

about:config Options Required for Testing Theme

Without these, Firefox will say the extension is corrupt and won't load. This also requires the nightly build of Firefox.

• xpinstall.signatures.required: false
• extensions.experiments.enabled: true

Building Extension

Just zip up manifest.json, userChrome.css and icons.