Something I’ve noticed in recent versions of Firefox (7 and up) is the lack of “http://” in the address bar. See?
Personally, I don’t like this. I’m a completionist, after all. I like the whole story from my web browsers. So here’s how to get your http:// prefix back.
Open Firefox, and in the address bar, type about:config
You’ll get a message saying that “This might void your warranty!” If you’re all set to take the leap, click I’ll be careful, I promise!
In the next screen that appears, type browser.urlbar.trimURLs in the Filter box at the top. Once it pops up, double-click to set the value to False.
Voila! You have your beloved http:// back!
If you want to go back to shortened URLs, simply follow the above steps and double-click the value to set it back to True.