Client-Side Stockfish WASM Engine
Analyze a Chess Game
Paste your PGN, upload a game file, or import directly from Lichess. Run deep engine evaluations and discover mistakes locally in your browser.
Local & Private
Engine analysis runs on your device via WebAssembly. Saved locally on this device.
Stockfish 18
Powered by the world's strongest open-source engine running inside dedicated Web Workers.
Move Quality
Clear move classifications: Optimal, Strong, Acceptable, Dubious, Mistake, and Blunder.