Removing duplicate tabs–unless you duplicate the tabs intentionally for some reason–is one of the ways to reduce the clutter on the tab bar. Even if you don’t open too many tabs, let’s say you only open around 40 tabs, sometimes you might still find one or two duplicated tabs. To prevent duplicated tabs, the autocomplete feature of Firefox displays suggested links as you begin typing an URL in the address bar, and the text “Switch to the tab” appears for the matching pages that are already opened in other tabs. This prevents you from opening the same site twice unless you intend to do so. But how to detect duplicated tabs if you open the links from existing pages? Meet LinksWatched.
LinksWatched is a restartless Firefox add-on that monitors links and warns users when it detects a duplicate tab. When you open a duplicate tab in foreground, the page is marked with a red frame. As for the page that is opened in background, the small pop-up message displayed on the right corner of your screen above the notification area lets you know that it is a duplicate page. This warning message also appears when you open the link in foreground. Clicking on that message will close the current tab and open the already-existing one.
The warning message and the red frame appears on duplicated tabs opened in another window as well.
While the warning message disappear automatically after a few seconds, the red frame stays there as long as the duplicate tab is opened. There is no option to remove this red border. This could be a little annoying when you actually want to open the same site in several tabs.
Tested version: LinksWatched 0.0.1.rev64