When researching for something we open more than a dozen tabs from various web sites and tend to forget whether we have already checked the same web site or web page before. Sometimes, we open the same web page twice in two different tabs. Opening the same web page twice or more than twice is not going to give us anything extra, but it takes up the system resources and might make Firefox work a tad slower. This can also happen if you have an old mouse and the button gets clicked erroneously several times over a link resulting in the same webpage being opening multiple times in different tabs.
If you find yourself opening up the same web page in many tabs, then you can seek the help of the Duplicate Tabs Closer extension available for the Firefox web browser. It can detect and automatically close duplicate tabs opened across a single Firefox session in the same window. It will fail to work if you open the same webpage in different Firefox windows.
Upon the installation, it places an icon in the toolbar and starts to monitor the tabs opened in the Firefox windows. It detects the identical tabs based on the URL, but you can choose to filter out the search or hash part. For example, http://www.trishtech.com/?s=malware and http://www.trishtech.com/?s=android will be treated as the same URL if you choose to ignore the search portion.
You can click on the toolbar icon for this extension to select an action to take when a duplicate tab is detected. You can choose to do nothing, display the panel from where you can choose what to do, or automatically close the duplicate tab.
Duplicate Tabs Closer can help you minimize the Firefox system resources usage by closing down the duplicate tabs if any were opened by mistake. It can also prevent the confusion caused through duplicate tabs when you are researching about a topic on the Internet.
You can get the Duplicate Tabs Closer extension from https://addons.mozilla.org/en-US/firefox/addon/duplicate-tabs-closer/.