What does the validator check?

It parses the header tags, strips comments and variations, then plays each move on a board that enforces the rules of chess. Any move that is illegal, ambiguous or malformed is reported with its move number and the legal moves in that position.

Does it fix errors automatically?

It fixes notation errors — 0-0 for O-O, dc for dxc5, e8Q for e8=Q, missing + and # signs. It cannot guess what a genuinely illegal move was meant to be; that is why it shows the legal alternatives for you to choose from.

Can I paste moves without headers?

Yes. A bare move list such as "1. e4 e5 2. Nf3 Nc6" is enough. The cleaned output adds placeholder headers you can fill in.

Why do handwritten scoresheets produce invalid PGN?

Players skip a move, write the wrong file, or forget to mark a capture. If you are typing up a scoresheet, ScanChess can read the photo, apply the same validation and let you correct moves on the board.

PGN Validator & Cleaner

Free tool · No account needed

Find the first move that does not work, get a clean seven-tag PGN back. Runs in your browser. Nothing is uploaded.

Is the game on a paper scoresheet? Scan it into PGN instead of typing it.

Scan an image Try the free example

Paste a PGN or a bare list of moves. The validator plays them out on a real board, points at the first move that does not work and lists the legal alternatives, then rewrites the game as a clean seven-tag PGN. Shorthand such as 0-0, dc or e8Q is normalized automatically. For what each header tag means, see what is PGN.

What this tool does

Exact error location

See the move number, the token that failed, and every legal move in that position.

Notation clean-up

Castling with zeros, missing check marks, lowercase pieces and promotion shorthand are corrected to standard SAN.

Standard output

The result is a Seven Tag Roster PGN wrapped at 80 columns that Chess.com, Lichess and ChessBase accept.

Nothing leaves your browser

Validation runs locally with chess.js. Paste tournament games without worrying about privacy.

How to validate a PGN

1
Paste the PGN, or just the moves, into the box.
2
Click Validate. Green means every move is legal; red points at the first problem.
3
Fix the move in your source (or in the PGN viewer) and validate again.
4
Copy or download the cleaned PGN.

Frequently asked questions

What does the validator check?: It parses the header tags, strips comments and variations, then plays each move on a board that enforces the rules of chess. Any move that is illegal, ambiguous or malformed is reported with its move number and the legal moves in that position.
Does it fix errors automatically?: It fixes notation errors — 0-0 for O-O, dc for dxc5, e8Q for e8=Q, missing + and # signs. It cannot guess what a genuinely illegal move was meant to be; that is why it shows the legal alternatives for you to choose from.
Can I paste moves without headers?: Yes. A bare move list such as "1. e4 e5 2. Nf3 Nc6" is enough. The cleaned output adds placeholder headers you can fill in.
Why do handwritten scoresheets produce invalid PGN?: Players skip a move, write the wrong file, or forget to mark a capture. If you are typing up a scoresheet, ScanChess can read the photo, apply the same validation and let you correct moves on the board.

Typing up scoresheets by hand?

Skip the typing. ScanChess reads handwritten scoresheets, validates every move the same way and lets you fix mistakes on the board. Free credits on sign-up.

Scan a scoresheet

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