Chessy
What Is FEN in Chess?
FEN (Forsyth-Edwards Notation) is a single line of text that encodes an entire chess position — piece placement, side to move, castling rights, en passant, and move counters — so any position can be saved or shared.
What's packed into a FEN string
A FEN string looks like rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 — that's the starting position. Each part encodes something specific: where every piece sits, whose turn it is, which castling rights remain, whether an en passant capture is possible, and how many moves have been played.
Why FEN is useful
Unlike PGN, which records a whole game move by move, FEN captures just one snapshot — a single position, with no history needed. That makes it perfect for sharing a puzzle, setting up an engine analysis, or jumping straight into the middle of a game without replaying every move to get there.
Where you'll see it
Nearly every chess engine, database, and website accepts FEN as an input format. Paste a FEN string into an analysis board and it instantly recreates the exact position, ready for you to study or continue playing from.
Frequently asked questions
What does FEN stand for?
Forsyth-Edwards Notation, named after its creators — a compact text format for describing a chess position.
What information does a FEN string include?
Piece placement, whose turn it is, castling rights, en passant availability, and move counters.
How is FEN different from PGN?
FEN describes a single position at one moment, while PGN records the full sequence of moves in a game.
Can I use FEN to set up a position on a chess engine?
Yes — nearly every engine and chess website lets you paste a FEN string to instantly load that exact position.