Free chess tool

FEN Board Viewer

Paste any FEN string and see the position on a real walnut board.

FEN (Forsyth–Edwards Notation) is the standard one-line text format for a chess position. Paste one below and this viewer draws the board, tells you whose move it is, and lists castling rights, en-passant target and move numbers. If the FEN is malformed, it tells you exactly what’s wrong instead of failing silently.

Example positions

Click to load one, then hit “Show position”:

What is a FEN string?

A FEN has up to six space-separated fields. Only the first is required to draw a board:

1. Piece placement — eight ranks from 8 down to 1, separated by /. Letters are pieces (uppercase = white, lowercase = black); a digit is that many empty squares. Each rank must total 8.
2. Side to move — w or b.
3. Castling — any of KQkq, or - for none.
4. En passant — the target square (e.g. e3) or -.
5. Halfmove clock — half-moves since the last capture or pawn move (for the 50-move rule).
6. Fullmove number — starts at 1, increments after Black moves.

FAQ

Does this check if the position is legal?

No — it reads the FEN and draws it exactly as written. It validates the format (each rank totalling 8, valid piece letters) but does not judge whether the position could arise in a real game.

Why is my FEN rejected?

The most common causes are a rank that doesn’t add up to eight squares, an invalid piece letter, or the wrong number of ranks. The error message names the exact rank so you can fix it fast.