The throbber is a little animated icon that notifies you whether a page is loading or has finished loading. Some people just find it annoying or even useless. Well, as for me, I keep mine though I understand why people don’t want the throbber. You have already have the throbber in the main window and you have individual throbbers for each of your tabs. Quite redundant.

While it doesn’t really affect Firefox performance, it’s another tweak to make your Firefox browser, your own.

Here’s how to remove the throbber:

• Open your userChrome.css (I recommend using ChromEdit Plus)
• Insert this code at the bottom: #throbber-box { display: none !important; }
• Save your userChrome.css
• Restart Firefox