I have two instances of Firefox running and want to take a tab into the other, when running fullscreen, you can't view the other instance.

Firefox does this sort of thing by default. Tabs will * '''drag from one window to another''' see additional notes under *drag along the tab bar to another position * on to the desktop to create a shortcut ** but to do that you drag the icon from the location bar not the tab * open in a new window, to do that drag them down or use a right click option. ** note move to group option also from right click Also see related articles *[[Use Tab Groups to organize a lot of tabs]] *[[Mastering the Tab Group Editor]] *[[Use bookmark folders to organize your bookmarks]] *[[Pinned Tabs - keep favorite websites open and just a click away]] *[[New Tab Page – show, hide and customize top sites]] -------- You say ''I have two instances of Firefox running and want to take a tab into the other, when running fullscreen, you can't view the other instance.'' I assume that you mean you have two separate Firefox windows open (slightly different from two instances of Firefox) # reduce the size if you wish to move tabs between the two windows # drag tabs from one to the '''tabs bar''' of the other, and insert it between or adjacent to an existing tab * note it is not possible to drag the last tab off a window. A window needs at least one tab (open a new blank tab as a workaround if you wish to move the last remaining tab) Please post back with how you get on. It may be a little confusing using a new browser and I am not sure if I have explained the things you need to know or not.