I would like to save those extra few pixels, since I'm often on the go on a laptop and overall customize FF.

Is there a way to shave off those extra pixels here? (Picture for reference)

Firefox's tab bar and address bar

1 Answer 1


I was just looking for the same thing! What about this ghack. Tested on Firefox 38.0.5, Yosemite 10.10.3.


Installing thintabs made the trick for me. But, according to the article, you can also do it manually:

The advantage is that you don't need to install add-ons for the operation, the disadvantage that it takes a minute longer to complete.

  1. Load about:support in the browser's address bar and hit enter.
  2. Locate the show folder button under Application Basics and click on it. This opens the profile folder using the system's default file browser.
  3. Open the Chrome folder there. If it does not exist, create a new folder and name it Chrome.
  4. Open the file userChrome.css in the Chrome folder. Again, if it does not exist create it.
  5. Add the following information to the file:

To change the tab toolbar height:

#TabsToolbar { height: 25px !important; }

To change the bookmarks toolbar height:

PersonalToolbar {height: 25px !important;}

The height parameter defines the new height of either bar. It is set to 25 pixels by default but you can change it to other values that work better for you.

Make sure that the following line of code is displayed at the top of the file once:

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

The full code looks like the following in userChrome.css

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */
#TabsToolbar { height: 25px !important; }
#PersonalToolbar {height: 5px !important;}
  • there you are @fixer1234 :) Jun 29, 2015 at 3:29

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