There are additional shortcuts as well. You can configure and use all of them at the same time. - There is a shortcut to open the new tab in a new window. - There is a shortcut to pop the current tab (or multiple highlighted tabs) out to a new window. - There is a shortcut to open a blank new tab to the immediate right of the current tab (i.e. instead of all the way to the right). Tip: Even without this extension, it is possible to middle click the refresh button to duplicate the current tab. Firefox version: https://www.crxsoso.com/firefox/detail/duplicate-tab-shortcut/ Source code: https://github.com/stefansundin/duplicate-tab