BestChessMove.xyz is a free online chess analysis board powered by Stockfish 18 — one of the strongest chess engines in the world, running entirely in your browser. Set up any position, paste a FEN, or replay a game to get instant evaluations, best-move arrows, principal variations and mate detection. No account, no downloads, nothing sent to a server.
EngineStockfish 18 · NNUE
RuntimeWebAssembly · multi-threaded
Library3,706 opening positions
PrivacyLocal-only · works offline
Questions
Everything you might reasonably wonder.
Is BestChessMove.xyz really free?
Yes. Engine analysis, best-move arrows, principal variations and unlimited positions are completely free, with no account required, no upload, and no daily limit.
Does the chess engine really run in my browser?
Stockfish 18 is compiled to WebAssembly and runs locally on your device. Positions never leave your computer, and analysis keeps working offline once the engine has loaded — you can disconnect and the page still works.
How do I analyze a specific position or paste a FEN?
Paste any FEN string into the FEN field in the Position panel, or drag pieces on the board to set up a position by hand. The engine re-evaluates immediately, and the opening name is detected automatically when the position is known.
How strong is Stockfish 18?
Stockfish 18 is one of the strongest chess engines ever built — well above human world-champion level on standard hardware. Its evaluation reliably finds the best move in almost any position once given enough depth.
Can I use it to study openings and endgames?
Absolutely. Step through moves with undo and redo, watch the evaluation bar and principal variation update in real time, and explore alternative lines from any position. Openings are detected against the Lichess opening book.
Do you store my games or analysis?
No. We store nothing about your analysis — there is no server to send it to. The only data we keep is the email address you optionally provide for the weekly puzzle, which you can unsubscribe from at any time.
A position a week. One puzzle, one paragraph, no spam.