The Encyclopaedia of Chess Openings classifies openings into five volumes, A to E, with codes from A00 to E99. B90, for example, is the Najdorf Sicilian. Several named lines can share one code.

Why does the name change as I add moves?

Each named line is a position. A game first reaches King's Pawn Game, then Sicilian Defense, then a variation of it. The page shows the deepest one, and lists the ones before it.

Does it find transpositions?

Yes. Positions are compared, not move orders, so the same position reached by a different order of moves gets the same name.

Can I paste a FEN instead of moves?

Yes. A FEN that is itself a named position gets its name. A position from the middlegame has no opening name of its own; paste the moves that led to it to see which opening the game came from.

Where do the names come from?

From the Lichess chess-openings data set, which its authors dedicate to the public domain (CC0). The names are in English, as in the data set.

Chess Opening Identifier

Free tool · No account needed

Paste a game or a FEN, get the opening and its ECO code. 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 game, a bare move list or a FEN and this page names the opening: its ECO code (B90, C65…) and its full name, down to the variation. It replays the game and looks up every position, not the move order, so a game that reaches the Queen's Gambit Declined by 1. Nf3 and 2. c4 is still called the Queen's Gambit Declined. The answer is the deepest named position the game reached, with the move that reached it and every named position before it. The names and codes come from the Lichess chess-openings data set, which is in the public domain.

What this tool does

Matched by position

Each position of the game is looked up, so transpositions are found and the name is the one the position deserves, whatever the move order.

The deepest named line

The result is the last named position the game passed through, with the move that reached it and the board as it stood.

PGN, move list or FEN

Paste a full PGN with tags and comments, a plain move list, or a single FEN. A file with several games lets you pick one.

Thousands of named lines

ECO codes A00 to E99 and the Lichess names for each line, matched in your browser. Nothing is uploaded.

How to identify a chess opening

1
Paste a PGN, a move list such as 1. e4 c5 2. Nf3, or a FEN. You can also choose a .pgn file.
2
Read the ECO code and the name of the deepest named position, and the move that reached it.
3
Check the list of named positions to see where the game went on the way.
4
Open the position in the analysis board, or analyze the whole game.

Frequently asked questions

What is an ECO code?: The Encyclopaedia of Chess Openings classifies openings into five volumes, A to E, with codes from A00 to E99. B90, for example, is the Najdorf Sicilian. Several named lines can share one code.
Why does the name change as I add moves?: Each named line is a position. A game first reaches King's Pawn Game, then Sicilian Defense, then a variation of it. The page shows the deepest one, and lists the ones before it.
Does it find transpositions?: Yes. Positions are compared, not move orders, so the same position reached by a different order of moves gets the same name.
Can I paste a FEN instead of moves?: Yes. A FEN that is itself a named position gets its name. A position from the middlegame has no opening name of its own; paste the moves that led to it to see which opening the game came from.
Where do the names come from?: From the Lichess chess-openings data set, which its authors dedicate to the public domain (CC0). The names are in English, as in the data set.

The game is on a paper scoresheet

Photograph the scoresheet and ScanChess reads the moves into a PGN, opening name included. A scoresheet scan costs 2 credits; new accounts get 10 free.

Scan a scoresheet

Guides for this tool

More free tools

All tools