Make sure that you do not run Firefox in full screen mode (press F11 or Fn + F11 to toggle; Mac: command+Shift+F).<br /> If you are in full screen mode then hover the mouse to the top to make the Navigation Toolbar and Tab bar appear.<br /> You can click the Maximize button at the top right to leave full screen mode or right click empty space on a toolbar and use "Exit Full Screen Mode" or press F11.<br /> Press F10 or tap the Alt key to bring up the "Menu Bar" temporarily if the Menu Bar is hidden. ---- See also: *https://support.mozilla.com/kb/how-do-i-get-firefox-button *https://support.mozilla.com/kb/why-are-tabs-top