Play Stockfish free
Play Stockfish 18 in your browser, from random moves to full strength, as White or Black.
Play
Stockfish 18 in the browser. Add a rule, or open a named mode with the rules already on.
Your move
How it works
- Set Stockfish’s strength with the slider.
- Add rules to make Stockfish stronger or weaker as you play.
- Undo takes back your move and Stockfish’s reply.
- After the game, you can review every move.
Your own rules
A rule is a trigger, an effect and an amount: engine top move, any other move, capture, non-capture, a blunder (graded as the review grades it), check or promotion, set to make Stockfish stronger or weaker. Named modes live under Game modes, with the rules already on; /play is the blank customiser.
The engine follows you
Stockfish’s rating goes from 0 to 3190. In a “don’t” mode, breaking the rule makes Stockfish stronger. In a “reward” mode, doing the thing makes it weaker. With no rules, it’s a normal game.
Summary, link and review
When a game ends you see how you did — blunders, mistakes and the costliest move — and you can open it as a full game review. Every finished game gets its own link. To start from a position instead, use the sandbox board.