I've searched long enough for this to put it here for other searchers (especially concerning spacing or margins). If you want the height of your tabs to be a bit smaller (including text of course), you can do that by editing your "C:\Users\[YourUSername]\AppData\Local\Mozilla\Firefox\Profiles\[Your profile]\chrome\userChrome.css" . Create one from "userChrome-example.css" if it doesn't exist. Here is the code you should add after "@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul")" : .tabbrowser-tabs { height: 18px !important; } .tabbrowser-tabs .tab-text { font-size: 80%; } .tabbrowser-tab { margin-top:0 !important; } .tabbrowser-tabs tab label { margin-top:-2px !important; height: 16px !important; }
Just stuff, you know.