Find the patterns behind your blunders
Review your Chess.com and Lichess games with Stockfish, ask Aesop, your AI coach, why a move went wrong, and turn your mistakes into puzzles you can train. Free, no signup.
10,000+ games analyzed
Move 22 · White to move
vs Opponent1234
78.4%
Your accuracy
Opening: Sicilian Defense, Najdorf · left book at move 12
Evaluation
Meet Aesop, your AI coach
Stockfish finds the best move. Aesop explains it. Pick any move in your game and Aesop tells you, in plain language, why it worked or failed and which habit to practise next.
After the game, Aesop reads your whole report and names the one thing to work on.
Explanations are written by Claude and grounded in Stockfish analysis, never guessed.
Nf6 is an understandable idea. It develops the knight and hits the queen on h5. But it leaves f7 defended only by the king. White's queen and bishop both aim at f7, so Qxf7 is checkmate. The move to find is g6, which attacks the queen and closes the diagonal. Next time, before developing, check every square next to your king.
The free chess analyzer that finishes the job
Most analyzers hand you a report and stop there. Chesslume grades every move of your Chess.com or Lichess games with Stockfish 18 and then rebuilds your worst calls as puzzles, so the review turns into practice. Unlimited reports, nothing behind a paywall, and no account is ever required to train.
Inside every game report
Each move earns a grade from Best to Blunder. The grade weighs how much a move shifted your winning chances instead of raw centipawns, so a quiet, sound move in a winning position never takes the hit. The evaluation graph traces the advantage across the whole game, which makes the turning point easy to find. Step move by move through the board, compare the engine’s top candidates, and see the opening name plus the move you left book theory. Want the detail on the grades? Read how move classifications work.
Turn your mistakes into training
Reading a report teaches you that a mistake happened. Training teaches you not to repeat it. Chesslume feeds your own blunders back into the puzzle trainer, so the position you misplayed returns to your board and you find the move you missed with your own hands. Unlike engine-only tools, the review is the start of practice, not the end of it.
Bring your games from anywhere
Drop in a Chess.com or Lichess username and Chesslume pulls your public game history through each site’s open API. No password, ever. Playing in a club or on another server? Paste the PGN text or upload the file. Every time control is fair game—bullet, blitz, rapid, classical—and the number of games you review is up to you.
Frequently asked questions
Is Chesslume free?
Yes. Reports, puzzles, and the trainers carry no cost and no daily cap, and nothing on this page asks you to register first.
How is this different from the Chess.com Game Review?
Chess.com keeps the detailed engine breakdown behind its Diamond plan and caps free accounts at one review a day. Chesslume runs the full Stockfish report on every game without a paywall, then converts your biggest mistakes into puzzles you can drill—the score is where practice starts, not where it ends.
What engine does it use?
Stockfish 18, the strongest open-source chess engine. The interactive board is analyzed right in your browser, while full game reports run on our own Stockfish server.
Is my data private?
Chesslume never asks for a Chess.com or Lichess password and never connects to your account—it reads only public game data through the official APIs, and it does not sell what it reads.
What does the report show?
A grade on every move from Best to Blunder, an overall accuracy score, the opening you played and where you left theory, an evaluation curve across the game, and the engine’s top choice in every position.
Do I need to create an account?
No signup wall: paste a username or a PGN and your first report is one click away. Ratings and streaks stay in your browser, so your progress survives between visits without a login.