Board editor

How to set up a position

Pick a piece from the palette, then tap squares to place it. Drag across the board to paint several squares at once, and tap a matching piece to take it off again. Choose the move tool to drag pieces around, or the eraser to clear squares. Start gives you the normal starting position and Clear empties the board.

Side to move, castling and en passant

A position is more than where the pieces stand. Say whose turn it is, which castling moves are still allowed, and whether an en passant capture is possible. Castling options switch off by themselves when the king or rook isn’t on its starting square, and en passant only lists squares where a pawn could really have just moved two steps.

What is a FEN?

FEN (Forsyth–Edwards Notation) is a single line of text that describes a whole chess position. The FEN box updates as you edit, and you can paste a FEN into it to load a position. Copy it to use in other chess apps, or share a link that opens this exact position in the editor.

Analyze it or play it out

When the position is legal, send it to the analysis board to see what Stockfish thinks, or play it out against one of our Stockfish bots. If something is wrong, like a missing king or a pawn on the back rank, the editor tells you what to fix.