Place the mouse cursor between the location bar and the search bar. The cursor should change to a resizer that you can drag left or right to change the width of the location bar and the search bar. See: http://support.mozilla.com/en-US/kb/Search+bar#Resizing_the_Search_bar See also [http://kb.mozillazine.org/Corrupt_localstore.rdf Corrupt_localstore.rdf] (MozillaZine KB) (caution: do not delete the localstore.rdf file in the Firefox program installation folder) The location bar and search bar have a flex property and take all available space. You can change the relative size of both with that resizer between the two bars, but that won't change the space that both take. You can add Space elements at the right of the bar in the "View > Toolbars > Customize" window to make the location bar shorter. You can set a specific width of those bars if you add code to userChrome,css Add code to [http://kb.mozillazine.org/UserChrome.css userChrome.css] below the @namespace line. @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */ See http://kb.mozillazine.org/Editing_configuration#How_to_edit_configuration_files #urlbar-container {max-width: 400px !important;} #search-container {max-width: 200px !important;} (adjust the width to your needs, no space before px)

Yes, I did manage to find out how to do it. But it should be made clear that the location bar and the search bar should be beside each other for this to work, I had two buttons between the two bars and the cursor does not change to a resizer. I moved the two buttons, then resized, then replaced the two buttons to their original position.