The usual hot keys work in the editor: Shift + arrow for select Ctrl + C for copy Ctrl + X for cut Ctrl + V for insert Ctrl + Z for undo Ctrl + Y for repeat (available only in case of no other edits occur since last undo)

Of course you can also select with the mouse and use your browser's editing features. (!) Linux and other UNIX OSes / X11: A left doubleclick selects and copies a word, and a click on the middle mouse key is insert.