Firefox 4 introduced the Switch-to-tab feature. From our Quick Guide to Firefox 4:
Switch to Tab – Numerous times I have so many tabs open and don’t realize that the new tab I just opened is a duplicate of one already open (but not visible). For example in the address bar I typed Hotmail, the new ‘smart location bar’ knows I already have this tab open and gives me the option to ‘Switch to Tab’. Update: This feature works for tabs open in another Firefox window as well. Typing % in the address bar will also display a list of all the tabs you have open.
It seems there is quite the backlash against the switch-to-tab feature. Not so much the feature itself, but that there is not an easy way to disable the feature. It can be disabled, but involves installing an add-on as well as doing an about:config tweak.
First off you will need to install the experimental Switch-to-tab blacklist extensions. Once it is installed (no restart needed):
- Open a new tab, paste & go about:config into the address bar.
- If needed, click the I’ll be careful, I promise button
- Filter for extension.switchToTabBlacklist.blacklist
- Double-click the entry
- Remove the existing value and paste in [“.*”] (make sure to include the brackets)
- Close the tab. switch-to-tab feature is now OFF