A coach, not a scoreboard

Most chess apps are built around playing as many games as possible, and leave the learning to you. That's fun, but it's not how most people get better. Improving at chess comes from understanding your mistakes, studying the ideas behind good moves, and practising them until they're yours, ideally with someone who can tell you what to work on next.

For most players that someone has never been available. A human coach costs more than a hobby usually justifies, and an engine gives answers without reasons. Walnut Chess is a free AI chess coach built to fill that gap. Like a good human coach, it watches your games and puzzles, works out what keeps costing you, and trains exactly that, explaining everything in plain words. It goes through the games you play on Chess.com and Lichess too. It's for players who want to understand the game, from people who have just learned the rules to club players trying to break through a plateau.

Free, and always free

Coaching has always gone to the players who could pay for it. We think that's the wrong filter. Walnut Chess is completely free: no subscription, no premium tier, no card, and every feature open to every player. That isn't an introductory offer; it's how Walnut Chess works, and it will stay that way. More on why.

What we believe

• Coaching should be free. Everyone who wants to get better deserves someone to explain their games.
• Explanations beat evaluations. A number from an engine is a summary. You need the reason. More on that.
• An AI coach must be right about the chess. Stockfish decides what's good; the coach explains it. How that works.
• Guidance, not autopilot. You think first and the coach responds. Help that plays for you teaches nothing.
• A good opponent is a matched one. You learn most against someone who plays like a real player at your level.
• Train what your games show. The best practice is aimed at the mistake you actually keep making.
• Memory needs practice. Spaced repetition and drills turn what you studied into what you play.
• Less, but better. One idea you understand is worth more than ten lines you half remember.
• Chess is for every age. A six-year-old deserves a patient coach too, which is why there's kids mode.

Credits

Move analysis and the chess AI are powered by Stockfish, the free and open-source chess engine, licensed under the GPL. The coach's words are written by Claude, Anthropic's AI model, working from Stockfish's analysis. Opening names and moves come from the Lichess chess-openings dataset, released under CC0. Thanks also to Google's Gemini and to open-weights models. Thank you to everyone behind them.