The board at /analyze is both a position editor and an analysis board. Set up the pieces or paste a FEN, play moves for either side, and switch Stockfish on when the position is ready.
What you can do on the board
- Drag pieces onto any square. The Clear button empties the board in one go.
- Paste a FEN to load a whole position. A link like /analyze?fen=... opens the position straight in analysis mode.
- Set the side to move and the castling rights that are still available.
- Flip the board to look from Black’s side.
- Play moves for either side: the board accepts legal moves only.
How to use the board
- Open the editor at /analyze?mode=setup.
- Build the position by dragging pieces or pasting a FEN. Pick the side to move.
- Press Start analysis. Stockfish shows the evaluation and lines and recomputes them after every move you play.
The engine behind the board
Stockfish 18 runs in your browser, at depth 15 for free and up to 22 with Pro. If the position is already in our evaluation database, the lines come from there without a search. How to read the evaluation and the lines is covered in the Chess Analyzer article.
When the board is better than importing a game
Importing is for reviewing a game you played. The board is better when there is no game:
- a position from a book or an article;
- an endgame or a tactic with only a few pieces;
- a line from your own game where you want to move one piece and see how the evaluation changes;
- a lesson with a student on a clean board.
Related
- FEN Analyzer: where to get a FEN and how to read it.
- Chess Analyzer: what the evaluation and engine lines mean.
- Free Chess Analysis: whole games from Chess.com, Lichess or PGN.
- Open the board editor.
FAQ
How do I set up a position on the board?
Open /analyze? mode=setup, drag pieces onto the squares or paste a FEN. Pick the side to move and press Start analysis.
Can I play out moves on the board?
Yes, for either side. The board accepts legal moves only, and while the analysis is on Stockfish evaluates every new position.
Does the board accept FEN strings?
Yes. Paste a FEN into the editor or open /analyze? fen=<FEN> as a link. Once the position is set up, Copy FEN gives you its string.
Which engine evaluates the position?
Stockfish 18 in your browser, at depth 15 for free and up to 22 with Pro. If the position is already in our evaluation database, the lines come from there.