Free Chess Game Review
Paste the PGN of any game and get a full review: an accuracy percentage for each player, every move classified, and a ranked list of the moves that actually cost the game. No account, no daily limit.
How to review a game
- Get your PGN. On Chess.com open the game, press Share, then the PGN tab, and copy the text. On Lichess the PGN sits under the board on the analysis page, or you can use the download button.
- Paste it above and pick a depth. Depth 12 is a good balance for a full game in a browser.
- Press Review this game. The engine searches every position in turn, so a 40 move game means about 80 searches. The progress bar shows where it is.
If you just want to see what the output looks like, press Load a sample game, which fills in Morphy's Opera Game from 1858.
How to read the report
Accuracy is a single percentage per player. It is computed from how much win probability each move gave away, not from how many moves matched the engine's first choice, which is why a quiet game can score high even when the moves are not engine perfect. Accuracy over 90 is a genuinely clean game at club level. Accuracy under 70 usually means at least one move threw away a large chunk of the result.
Move labels run from best and excellent through inaccuracy, mistake and blunder. The boundary between them is win chance loss, not centipawns: giving away five percent of your winning chances in a sharp position matters more than a two hundred centipawn swing in a position that was already lost. That is the same thresholding the Chess DNA app uses.
The moves that cost the most table is the part to actually study. It sorts your errors by how much win probability they gave away and shows the move the engine preferred. Two or three moves usually account for the whole result.
What "free" means here
There is no account, no email, no daily cap and no watermark. The engine runs in your browser, which is why this is possible: there is no server bill to recover.
The honest trade is speed. A hosted service can throw a cluster at your game and finish at depth 20 in seconds. A browser tab searches one position at a time, so a long game at high depth takes a few minutes. If you want depth 18 across a lot of games without waiting, that is what the Chess DNA app does after you connect an account.
One game is not a diagnosis
A single review tells you what went wrong in one game. It cannot tell you what goes wrong in your chess, because a single game cannot separate a bad day from a habit.
The useful question is which mistake repeats. Chess DNA analyses your recent games together and sorts every error into nine weakness themes: missed fork, missed pin, missed skewer, back rank weakness, hanging pieces, missed tactic, opening inaccuracy, endgame technique and middlegame tactics. Seeing that eleven of your last thirty losses share one theme is a different kind of information from seeing one blunder on move 24.
Frequently Asked Questions
Is this chess game review really free?
Yes. There is no account, no email, no daily limit and no payment. Stockfish runs inside your browser rather than on a server, so there is no cost to pass on.
Do I need an account to review a game?
No. Paste a PGN and press the button. Nothing is stored and nothing is uploaded, the analysis happens on your own device.
How is chess accuracy calculated?
Each move is scored by how much win probability it gave away compared with the best move, and those per move scores are combined into one figure. The tool above uses the same win chance model and the same accuracy curve as the Chess DNA app, so the numbers match.
How long does a game review take?
It depends on depth and game length. At depth 12 a 40 move game is typically a couple of minutes in a browser, because the engine has to search roughly 80 positions in sequence. Lower the depth for a faster answer.
How is this different from Chess.com Game Review?
Chess.com gives free members a limited number of reviews per day and gates the rest behind a paid plan. This page has no cap. Chess.com adds narrated commentary, which this tool does not; what you get here is the engine analysis, the classifications and the accuracy figure.
Can I review a game I played over the board?
Yes, as long as you can write the moves out as a PGN. A bare move list starting "1. e4 e5 2. Nf3" is enough, the header tags are optional.
