I have just upgraded to the latest version of Firefox. While there are many new features in 3.5, the one that you will probably notice first is the addition of a button to the right of your tabs that will open a new blank tab.

Since I use shortcut keys to open a new tab this button is pretty much useless to me. I like to keep my browser as uncluttered as possible. Fortunately, if you aren’t afraid of some minor text editing you can remove this button in about one minute.

You’ll need to find your user profile for Firefox which contains the userChrome.css file. On my XP computer it is located here:

C:\Documents and Settings\<your_account>\Application Data\Mozilla\Firefox\Profiles\ftz0ce5v.default\chrome

On OS X you will find this file here:

~/Library/Application Support/Firefox/Profiles/ftz0ce5v.default/chrome/

On Windows 7:

%appdata%/Mozilla/Firefox/Profiles/ftz0ce5v.default/chrome

Note that ‘ftz0ce5v’ is randomly generated by Firefox so you will see something slightly different. Once in this directory you should see a file named ‘userChrome-example.css’. Make a copy of this file in the same directory and rename it to ‘userChrome.css’.

Open the file you have just created an add the following line:

.tabs-newtab-button {display: none}

Restart Firefox and you will see the button is gone.