If you’re like me then you’re constantly thinking of new ways to tweak Mozilla Firefox. This morning I installed an addon called Vertigo. This extension stacks Firefox tabs vertically on the left-hand side of your browser. It worked well enough, but I soon grew tired of having to click twice to a close a tab.

I uninstalled Vertigo and with it went the close button on each of my tabs. To fix this I opened up Firefox’s advanced configuration by typing about:config in the address bar. I filtered by browser.tabs.closeButton and changed the integer value to 1.

The close buttons immediately reappeared. Alakazam!

For the curious:

0 - Close button on active tab only.
1 - Close button on every tab.
2 - No close buttons.
3 - Close button at the end of the tab bar (ala Firefox 1.5).