Credits pay for questions to the AI coach. They never expire.
Play Stockfish, challenge our AI engine Nexuron, get coached on every move, analyze your Chess.com or Lichess games, estimate your ELO, take on AI models in the Arena, solve puzzles, and replay famous games.
PlayStockfish lets you play chess online against Stockfish, the world's strongest open-source chess engine, with no sign-up required. Pick a difficulty that matches your level, from beginner-friendly bots to full engine strength, and improve your game one match at a time.
Fancy a different opponent? Play Nexuron, our dedicated AI chess engine created entirely with AI prompts. It thinks inside your own browser, and an adjustable search-depth slider lets you choose exactly how far ahead it calculates.
Want to know why you lost? Coaching mode plays a normal game while a second Stockfish, running at maximum skill, reviews every move you make — blunders are highlighted on the board and the tactics you missed are drawn on as arrows.
Already played the game somewhere else? Analyze any chess game by entering your Chess.com or Lichess username — or by pasting a PGN. Stockfish 18 reviews every move at full strength and marks the inaccuracies, mistakes, blunders and missed wins, scores both players for accuracy, and then hands your own mistakes back to you as practice positions.
Want more than a single game? Estimate your chess ELO rating with our 3-game rating test, sharpen your tactics with chess puzzles (mate-in-2 to mate-in-5), replay famous chess games like the Immortal Game and Deep Blue vs Kasparov, and watch or challenge large language models in the AI Chess Arena.