Play against one of the strongest chess engines in the world and master every opening — all running locally in your browser. No accounts, no downloads, completely private.
Challenge the Stockfish engine at 8 difficulty levels, from Beginner (~400 Elo) to Maximum (~3500 Elo). Includes evaluation bar, move history, and FEN import/export.
Browse, practice, and quiz yourself on 150+ chess openings. Covers all major ECO categories from the Sicilian Defense to the King's Indian.
Stockfish is an open-source chess engine rated above 3500 Elo at full strength, consistently ranked among the strongest in the world.
Everything runs locally in your browser using WebAssembly. Your games and progress never leave your device. No server, no tracking.
Our database covers 150+ named openings across all ECO categories, from beginner-friendly openings to advanced Grandmaster theory.
Practice specific opening lines with instant feedback, or test your knowledge in quiz mode. Track your streak and improvement over time.