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Chess AI Analyser

Free chess game analyser online — analyze chess positions and moves with Stockfish 18. AI explains every move.

Analyze Chess Position Online

Our chess analyser breaks down every move in your game. Paste your PGN and get detailed feedback on each position with best move suggestions.

Chess Board Analyser

Powered by Stockfish 18, the strongest chess AI. Evaluates positions at depth 18-30 for grandmaster-level analysis on every move.

Analyze Chess Moves

See move classifications: brilliant, great, best, good, inaccuracy, mistake, and blunder. Understand exactly where you went wrong.

Chess Game Analyser

Upload any chess game. Get accuracy scores for both players and detailed move-by-move breakdown.

Free Chess Analyser

No downloads, no registration required. Analyze chess games free online directly in your browser.

Chess Move Analyser

Find the best continuation for any position. Our analyser shows what you should have played and calculates expected points lost.

How to Analyze Your Chess Games

Analyzing your chess games is the single most effective way to improve. After every game, review your moves against the computer's suggestions to find mistakes, missed tactics, and better alternatives.

Simply copy your game's PGN from any chess platform and paste it above. The analyser classifies each move as brilliant, great, best, good, inaccuracy, mistake, or blunder — with accuracy scores for both players.

Free Chess Analysis with Stockfish 18

Chess analysis is a move-by-move review of a chess game that identifies mistakes, blunders, and brilliant moves.Chess Calculator's analysis tool uses Stockfish 18 — the world's strongest chess engine — to rate each move and generate accuracy scores for both players.

Our chess analysis tool is a complete chess board analyzer, PGN analyzer, and chess game reviewer powered by Stockfish 18 — the same engine grandmasters use to prepare for world championships. Paste any PGN and you get a full game review on the chess analysis board: move classifications, accuracy scores, brilliant moves and blunders flagged, with AI coach commentary that explains what happened at critical moments.

This is a true free chess analysis — no daily limits on game review, no paywall on the core analyzer, no signup required to paste a PGN and see the evaluation graph. The analysis runs in seconds, so you can review a game right after you finish playing instead of waiting for a background job to complete.

What the Chess Game Analyzer Shows You

  • Move-by-move classification — every move labeled as brilliant (!!), great (!), best, good, inaccuracy (?!), mistake (?), or blunder (??).
  • Accuracy score for White and Black — a single number showing how close each player came to engine-perfect play across the whole game.
  • Evaluation graph — plots the position evaluation across the game so you can see exactly when momentum shifted.
  • Best moves at every decision point — including the ones you missed, with the principal variation showing what should have happened.
  • AI coach commentary — plain-language explanations of why each key move worked or failed, in 19 languages.

How to Analyze a Chess Game

Copy the PGN from wherever you played — any chess board or PGN file — and paste it into the analyzer above. Within a few seconds, the chess game analyzer has reviewed every move and you can step through the game to see what you should have played instead.

The pattern: look at your accuracy score first, then jump to the moves marked as mistakes or blunders. For each one, read the AI coach's explanation. One blunder properly understood is worth more than ten games played without analysis.