PGN analyzer

Paste a PGN, pick a game, analyse it

One game or a whole tournament file. The analyzer reads the PGN, lists every game with its opening, lets you export a clean copy and sends any game to the Stockfish review with one click.

Free · runs in your browser

Analyse one game or a whole PGN file

Paste a PGN or upload files with hundreds of games
Filter by player, result, opening and date
Send any game to a full Stockfish review

Open the PGN database No account, no download.

What happens to your PGN

Parsing happens in your browser with chess.js, a widely used open-source move validator. Each game is replayed from the first move; if a move is illegal the game is set aside with a note saying where it went wrong, and the rest of the file is still read. Nothing is uploaded. When you click Analyze, the game is handed to the analysis board in the same tab and Stockfish runs on your device.

Openings are identified by matching positions, not move orders, against a table of about 3,600 named ECO lines derived from the open Lichess openings database. A game that reaches the Najdorf by an unusual order is still a Najdorf.

A minimal valid PGN

[White "Anand"]
[Black "Carlsen"]
[Result "0-1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 0-1

Headers are optional. Even a bare move list such as 1. e4 e5 2. Nf3 is accepted.

When to use which tool

One game, full report. Paste it on the analysis board or here and click Analyze. You get accuracy, every move graded, the evaluation graph and key moments.
Just the mistakes. The blunder checker runs the same engine but shows only the moves that cost you, each with a diagram and the better alternative.
Many games. This page. Read the file, scan the openings and results, pick the games worth your time.
Games from your online account. Skip PGN entirely and import by username from Chess.com or Lichess.

Analysis time scales with the number of moves and the depth you choose: roughly a second per move at the Fast setting on a laptop, three to five at Balanced. A forty-move game at Balanced is about three minutes of background work while you read the opening guide.

PGN questions

What is a PGN file?

Portable Game Notation is the plain-text standard for recording chess games: a block of tags in square brackets (Event, Site, Date, White, Black, Result and so on), then the moves in algebraic notation with optional comments in braces and variations in parentheses. Every chess site and program can export it.

Where do I get the PGN of my game?

Chess.com: open the game, click the Share icon, choose PGN, copy. Lichess: open the game, scroll below the board, click the PGN text or the download icon. Chess apps and tournament sites usually have a Download PGN button. Or skip the copying and import by username on our Chess.com and Lichess pages.

Can it handle a whole database at once?

Yes. Paste or upload a file with many games and the table lists them all with players, result, opening and length. Each row has its own Analyze button, and Open all in analysis lets you pick from the list inside the analysis board. Files up to 5 MB, around three to five thousand games, are fine.

What does the parser tolerate?

Clock and evaluation comments like {[%clk 0:09:58]}, variations in parentheses, missing headers, Windows and Mac line endings, numeric annotation glyphs such as $1, and the black-move numbering Chess.com uses (12... Nf6). It rejects a game only when a move is actually illegal, and tells you which one.

Why export a cleaned PGN?

Imported PGNs often carry clock comments and oddly formatted headers. The exported file re-serialises every game in standard seven-tag form with clean movetext, which some older programs need before they will import.