Play Stockfish free
Stockfish 18 in your browser, from 0 Elo to full strength. No account, no daily limit, no game leaves your device.
Play
Your move
Your own rules
A rule is a trigger, an effect and an amount: engine top move, any other move, capture, non-capture, a move that loses 1.00 or more, check or promotion, set to gain or lose Elo. Named modes below start with the rules already on; /play is the blank customiser.
The engine follows you
The number that moves is Stockfish's rating, between 0 and 3190. Gain Elo makes the game harder; lose Elo makes it easier. On a “don’t” mode, breaking the rule raises Stockfish. On a “reward” mode, doing the thing drops it. An empty rule list is an ordinary game.
Game URLs and review
Each game has its own link that replays it. A finished game opens as a game review, or set a position up first on the sandbox board.