Chess Notation Tools

Render a FEN position as an 8x8 ASCII board (White at the bottom) plus a piece-by-square list.

Validate a chess FEN: syntax of all six fields, king and pawn counts, castling and en passant consistency, piece totals.

Material balance from a FEN: standard 1-3-3-5-9 point totals per side, difference and piece lists.

Parse PGN tag pairs, check the Seven Tag Roster, result token and date format, and count the moves in the movetext.

Squares a knight, bishop, rook, queen, king or pawn reaches from a square on an empty board, with the count.

Distance between two chess squares as king moves, rook moves, bishop moves and knight moves on an empty board.

File, rank, light or dark colour, 0-63 index, diagonals and mirror squares for a chess square like e4.

Classify a chess time control (bullet, blitz, rapid, classical) from base minutes and increment, with estimated length.