Audit ChessAUDIT CHESS

How it works

How to analyze your chess games with Audit Chess

Audit Chess turns your real Lichess and Chess.com games into a training plan in three steps. Enter your username, let Stockfish analyze every game in your browser, and get a full review, puzzles from your own blunders, and a ranked list of your weaknesses. It is free, needs no account, and nothing is uploaded - the analysis runs on your device.

  1. 1

    Enter your username

    Paste your Lichess or Chess.com username and pick a colour. There is nothing to install and no account to create - you start in one click.

  2. 2

    Stockfish analyzes in your browser

    Audit Chess pulls your public game history and replays every game through Stockfish running locally in a Web Worker on your own device. Nothing is uploaded to a server - the analysis happens on your machine.

  3. 3

    Get your review, puzzles and weaknesses

    You get move-by-move game review with accuracy scores, an opening tree, every opening ranked by result, your endgame and playstyle profiles, blown-wins detection, activity analytics - and puzzles built from your own blunders. You can also scout an upcoming opponent.

Analyze your games →

Technical Details

  • Engine: Stockfish 16, compiled to WebAssembly (WASM)
  • Analysis depth: 15 ply per position
  • Accuracy method: Centipawn loss (CPL) — the difference between the eval of Stockfish's best move and the eval of the move you played. Average CPL across all moves produces the accuracy score.
  • Move thresholds: Best (0 CPL), Good (<10), Inaccuracy (10–49), Mistake (50–99), Blunder (≥100)
  • Puzzle depth: Solutions verified at depth 12, re-evaluated at depth 14 on solve
  • Data sources: Lichess public API, Chess.com published game API
  • Privacy: No game data is sent to Audit Chess servers. Analysis runs entirely in your browser.

Frequently asked questions

How does chess game analysis work?+

Each game is replayed position by position through a chess engine (Stockfish) that evaluates every move. Moves that lose evaluation are flagged as inaccuracies, mistakes or blunders, and the drop across a game becomes an accuracy score. Audit Chess does this for your whole history at once.

Is Audit Chess really free with no account?+

Yes. It is free and requires no account or sign-up. You enter a public username and analysis begins.

Is my chess data uploaded anywhere?+

No. Stockfish runs in your browser, so your games are analyzed on your own device rather than sent to a server.

How many games can it analyze?+

Audit Chess analyzes around 1,000 games in under a minute and scales to about 5,000.