Frequently asked questions
Is Chess Analytics & Replay really free?
Yes. There is no account, no subscription, and no paywall. The tool runs in your browser and pulls public data from the Chess.com API. The site may display advertising to keep it running, but every feature is free to use.
Do you store my data or my search history?
No. Everything happens in your browser. We have no accounts, no databases of users, and we do not store your search history, IP address, or any personal identifier. See the Privacy Policy for the full picture.
Where does the chess data come from?
Player profiles, statistics, archives, and games come from the public Chess.com API. This is the same public data visible on Chess.com. Position evaluation is done locally in your browser by the Stockfish 18 engine.
What is Stockfish?
Stockfish is one of the strongest chess engines in the world, and it is open source. This site runs a compiled version of Stockfish 18 directly in your browser, so positions are evaluated locally without any server round-trip.
Why is a move labeled a mistake when I was clearly winning anyway?
Engine classifications compare each move against the best move in that exact position. In a winning position, even a slightly imprecise move can look like a big drop in evaluation. The label says the move was not the best available, not that you lost the game.
Can I analyze any Chess.com player, or only myself?
Any player with a public profile. Type any username and you will see their ratings, recent games, win rates, and opening data. It is a useful way to scout opponents or to learn from stronger players.
How far back can I go?
Chess.com publishes monthly game archives. By default the tool loads recent games, and you can pick any older archive month from the archive selector to analyze a different period.
Why does my game review differ from Chess.com’s own review?
Different tools use different engine depths, evaluation times, and classification thresholds. Chess.com uses its own rules for labels like "brilliant." This tool uses its own fixed thresholds with Stockfish 18. Minor differences in labels are normal and expected.
Is this site affiliated with Chess.com or Stockfish?
No. This is an independent project. It uses the public Chess.com API and the open-source Stockfish engine, but it is not affiliated with, endorsed by, or sponsored by either.
Why is there a loading screen sometimes?
That appears while the tool fetches data from the Chess.com API and while Stockfish evaluates positions locally in your browser. Long analyses take a few seconds, especially on slower devices.