Tic-Tac-Toe
Two players, or play against an unbeatable computer.
Classic Tic-Tac-Toe — play locally against a friend, or against the computer on Easy or Unbeatable difficulty. Tracks the score across rounds and works full-screen on mobile.
Frequently asked questions
Can I play against a friend on the same device?
Yes — that's the default mode. Pass the device back and forth; X always goes first.
How good is the "Unbeatable" computer opponent?
It uses the minimax algorithm to always play the mathematically optimal move — it can't be beaten, only drawn, no matter how you play. "Easy" instead picks a random legal move, so it's beatable and more relaxed.
Is my score saved?
Yes — wins, losses, and draws are kept in your browser (not on any server) so the score persists between visits until you reset it.
Does this work on mobile?
Yes — tap to place a mark, and the fullscreen button expands the board to fill your screen, which works well on a phone.