YouTube Popout Player

Overview

Open any YouTube video (including playlists) in a popout player, either as a new browser window or a new tab in your current browser window.
Show or hide the video player controls in the popout player.
Automatically resume playback of the video when the popout player opens.
Automatically loop videos (both single videos and playlists) in the popout player.
Customize the size of the popout player, either as a fixed size or as a percentage of your screen’s resolution.
Close the original video when the popout player opens.
Firefox Only Add custom text to the popout player’s window title (for scripting).
Keyboard shortcut for opening the popout player.

For more information, head to the YouTube Popout Player website.