Plychess
Back to Encyclopedia
TechnicalLast Updated: 2026-07-08

FEN (Forsyth-Edwards Notation)

"A standard notation for describing a particular board position of a chess game."

Interactive Demonstration

8br
bn
bb
bq
bk
bb
bn
br
7bp
bp
bp
bp
bp
bp
bp
bp
6
5
4
3
2wp
wp
wp
wp
wp
wp
wp
wp
1awr
bwn
cwb
dwq
ewk
fwb
gwn
hwr

Visualizing the Concept

Use the interactive board to explore this position. Understanding FEN (Forsyth-Edwards Notation) is much easier when you can visualize the pieces in action.

Current FEN
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
Open in Analyze Lab

In-Depth Explanation

Forsyth-Edwards Notation (FEN) is a standard system for describing a specific board position using a single line of text. It provides all the necessary information to restart a game from that exact moment, including piece placement, active color, castling rights, en passant targets, and move clocks.

Frequently Asked Questions

How is a FEN string structured?

A FEN string has six space-separated fields: piece placement, side to move, castling rights, en passant target square, halfmove clock, and fullmove number.

What's the difference between FEN and PGN?

FEN describes a single position; PGN records an entire game move by move. FEN can be embedded inside PGN via the [FEN] header when a game starts from a non-standard position.

How do I validate a FEN string?

Use the Plychess FEN Validator to check syntax, piece counts and rule consistency, then load the position into the interactive board or Stockfish analysis.

Want to master your chess openings?

Join thousands of players who use our cloud repertoire lab to store and train their secret weapons.

Get Started with Repertoire Master (PRO)