6 Essential about:config Tweaks
About:config is amazingly powerful – it lets you change almost every aspect of how Firefox functions. There are a few settings that we think are essential to change. Make these tweaks first when you encounter a fresh install of Firefox.
browser.urlbar.autoFill = True
Enable auto-complete for URLs when typing into the location bar.
browser.sessionstore.max_tabs_undo = 15
Increase the number of closed tabs that firefox has stored in its cache to 15.
browser.tabs.tabMinWidth = 75
Show more tabs in a single window by narrowing the minimum width of a tab.
browser.search.openintab = True
Automatically open new search results in a new tab
middlemouse.paste = True
Use the middle mouse button to paste text from your clipboard.
browser.blink_allowed = False
Disables annoying text with the Blink tag.