Play for free against the computer, a friend by link, or a random opponent. Tic tac toe (also known as noughts and crosses, or Xs and Os) is a simple classic for kids and grown-ups alike. Play it free in your browser with no sign-up: against the computer, with a friend over a shared link, or against a random player online. Pick a 3×3, 4×4, 5×5 or 6×6 board and start a match.