Game Review
Give this page the games of one player, and the engine reviews every move. It names the weaknesses that cost the most, shows the moments that prove it, lists the strengths, and builds a set of positions to practice, drawn from your own games and from positions like them in the Lichess puzzle database. Each practice position is played for several moves against the engine and graded. Run the page again on your next games and the trend shows whether the work paid off.
Limits: up to 60 PGN files per drop and 7 MB in total, up to 400 games in one review, games of 5 to 300 moves and at most 256 KB each. A review of 30 games at the standard setting takes about ten minutes on a laptop; the page shows an estimate before it starts and can be stopped at any time.
Where your games go. The files stay in your browser. The engine, the puzzle positions, and the report all run and live here. The games, the engine's notes on them, the report, and your practice record are kept in this browser until you remove them with the buttons in step 1, and never leave it. Two optional actions send something, and each says so where you start it. Sharing a review stores the findings and the practice positions in this site's database under a random link that only signed-in readers can open, until you revoke it; your game files are never part of it. Signed in, each finished review and your practice on its positions are kept in your account as well, ten at a time, until you remove them or your account is removed after two years without a visit. Fetching games by username sends that username and the number of games you asked for to chess.com or lichess.org. The practice positions and the replay opponent's network are fetched from this site by theme, opening family, and strength, so this site's host can see those names, and nothing else. Apart from that optional username fetch, no game, name, or move leaves your browser.
1. Games
Drop PGN files here, or choose files. Exports from chess.com and Lichess, and games typed up from a score sheet, all work.
Paste games instead
Fetch games by username
The username you type and the number of games you ask for are sent to the site you pick, and nothing else. Games played over the board are not there, so drop those as files as well.
No games loaded yet.
2. Player
Tick every name that is you. A player often has one name on chess.com, another on Lichess, and a third on the tournament score sheet.
3. Review
The engine is Stockfish 18, downloaded once (about 7 MB) and run in this browser. Every position gets a quick search; the moves that lost something get a longer one, plus a search of what the opponent was threatening. Games already reviewed in this browser are not searched again.
4. Profile
By phase
Weaknesses
Ranked by what they cost per game. Each one lists the moments behind it; press one to see it on the board.
Strengths
Openings
Every game
Trend
Board
5. Practice
Each position asks for several moves. A puzzle from the database has one right answer per move, like a Lichess puzzle, and then continues against the engine, unless the solution ends in checkmate, in which case the solution is the whole score; a moment from your own game is played against the engine from the first move. A position you pass comes back after a few days, and one you fail comes back tomorrow.
Engine: Stockfish (GPLv3) via stockfish.js. Practice positions come from the Lichess puzzle database (CC0), and opening names from lichess-org/chess-openings (CC0). Replay opponents are the Maia networks, run with ONNX Runtime in this browser. Piece images by Colin M.L. Burnett (CC BY-SA 3.0).