Play a full game of chess against the computer, right here in your browser — no downloads, no account, no ads between moves. The opponent is Stockfish, the open-source engine that has won the world computer chess championship again and again, running entirely on your device. Pick your level honestly: Easy plays like a casual club beginner and drops a piece now and then, Medium is a real fight for most social players, and Hard is the full-strength engine that grandmasters use for analysis.
Click one of your pieces and the dots show every legal move. Captures are ringed in red, your last move stays highlighted, and pawns promote to queens automatically. Undo lets you take back a blunder — the computer does not mind.
How to play
- Choose a level and a color. Medium and White are the friendly defaults. Changing either starts a fresh game.
- Click a piece, then click its target square. Dots mark quiet moves, red rings mark captures. The move list under the board records the game in standard notation.
- Use Undo freely. It takes back your last move and the computer’s reply, so you can explore the line you wish you had played. Flip board turns the diagram around at any moment.
What is Stockfish, and how is it running on a web page?
Stockfish is a free, open-source chess engine — the strongest in the world — rated well above 3400 Elo at full strength, hundreds of points beyond any human. Normally it runs as a separate program that chess apps talk to with text commands (the UCI protocol). Here, a JavaScript build of the engine runs inside a background worker in your browser: the position is sent to it, it thinks for a moment, and it answers with its best move. The engine file (about 1.6 MB) downloads once from a public CDN and is cached by your browser. If it cannot load for some reason, this page falls back to a small built-in practice engine and tells you so — the game never just stops.
The three levels, honestly explained
Easy limits Stockfish’s skill setting to its lowest range and searches only a few moves deep. It will still punish a hanging queen, but it makes the kind of positional mistakes a human beginner makes — a fair first opponent. Medium raises the skill and depth to a level that beats most casual online players; you will need real tactics to win. Hard is essentially full strength: deep search, no charity. Beating Hard means playing the game of your life — most players use it as an analysis sparring partner and try to survive to an endgame.
Three tips for beating the computer
Do not hang pieces. At Easy and Medium, most wins come from simply taking free material. Before every move, ask what the computer’s last move attacks. Develop and castle. Engines punish a king stuck in the center; get your knights and bishops out, castle early, then fight for the middle. Use Undo as a teacher. When the computer plays a move that surprises you, take the position back and try the other line — understanding why its move was strong is worth more than the result of one game.
Try playing Black, too
Most casual players only ever take White, but Black teaches defence: you learn to equalise, to spot threats one move earlier, and to counterpunch instead of drifting. Switch sides in the “Play as” menu and Stockfish will open the game for you. Watching its first few moves from the other side of the board is a free lesson in what a strong opening actually looks like.
Private, instant, free
The whole game — board, rules and engine — runs on your device. There is nothing to install and no server ever sees your moves. It works on phones and tablets too; the board scales to your screen, and a game in progress survives in the page until you reload.
Related tools
Jugar Ajedrez contra la Computadora — versión en español · Chess Tips for Beginners · Trivia Quiz.
Embed this tool on your website — free
Copy the code below to add this working tool to your own page. A small credit link stays with it — that’s all we ask.