Yes, the standard method is to make the "source" window (the one you want to move tabs ''from'') resizable so you can drag individual tabs from its tab bar to the "destination" window, which you would generally want immediately behind it. I am aware of some extensions which might work for you, but I haven't tried them myself): * Window Master - has a merge windows command on the toolbar context menu: https://addons.mozilla.org/firefox/addon/monitor-master/ * Tab To Window - adds ability to move a tab to a particular other window to the tab context menu: https://addons.mozilla.org/firefox/addon/tab-to-window/ If you try one or both of those, please let us know how well they address your needs.