Chess Analysis and Game Review
Import a game from Chess.com or Lichess, or paste a PGN. Stockfish reviews every move in your browser: accuracy, blunders and the best move, with no daily limit.
How the free chess game review works
- Bring your game. Type your Chess.com or Lichess username to load your latest game, or paste any PGN.
- Stockfish analyzes every move. The engine runs on your device, so the review is free, private and unlimited. Most games finish in a few seconds.
- Read your report. See both players’ accuracy, an evaluation graph, every inaccuracy, mistake and blunder, and a short explanation of your three biggest mistakes with the move you should have played.
What your chess analysis shows
- Accuracy for both sides, using the open Lichess formula. How chess accuracy works.
- Move-by-move quality: best moves, inaccuracies (?!), mistakes (?) and blunders (??).
- Evaluation graph of who was winning at each moment; click it to jump to that position.
- Your key mistakes explained: what went wrong, what the engine preferred, and the line that follows.
- Annotated PGN download to keep the review or open it in another program.
Want to explore a single position instead? Use the chess analysis board or set one up in the board editor.
Review games from Chess.com and Lichess
Already played today? The Chess.com game review and Lichess game review pages explain where to find your games and how the review compares with each site’s own analysis. Games are read from each site’s public API in your browser; we never ask for your password.
Frequently asked questions
Is the chess game review really free and unlimited?
Yes. The engine runs in your own browser, so a review costs us nothing and there is no daily limit and no sign-up. Review as many games as you like.
Which engine analyzes my game?
Stockfish 19 (the lite build), compiled to WebAssembly and running on your device. Every position is analyzed at depth 12 and your three biggest mistakes get a deeper look at depth 18. On slow phones the review switches to depth 10 so it still finishes quickly, and tells you when it did.
How is my accuracy calculated?
We use the open formula published by Lichess: each move is scored by how much it lowered your winning chances, and the game score combines those move scores. The chess accuracy page explains the maths and why Chess.com and Lichess can give the same game different numbers.
What do Best, Inaccuracy, Mistake and Blunder mean?
They describe how many percentage points of winning chances a move gave away: an inaccuracy loses 5 or more, a mistake 10 or more, a blunder 15 or more. Best means you played the engine’s top move or lost almost nothing.
Can I review a game from Chess.com or Lichess?
Yes. Enter your username and we fetch your recent public games straight from Chess.com or Lichess in your browser, then review the latest one. You can pick another game from the list. ChessAnalysis is not affiliated with Chess.com or Lichess.
Do you store my games?
No. Games are fetched and analyzed in your browser and are not uploaded to our server. You can download the annotated PGN to keep a copy.