Chess Solver
Set the position. The solver answers it before you finish letting go of the piece.
Chess Solver explained, plus the FAQ
How to solve a position
- Build the position on the board, or paste a FEN under it. A FEN loads the instant it is pasted.
- Set the side to move. A puzzle that looks unsolvable is usually a puzzle with the wrong side to move.
- Press solve. Tap any of the three answer cards to play that move and keep solving from there.
There is no account, no sign in, and no limit on how many positions you can check. Nothing on this page is gated.
Solving a tactics puzzle
A tactics puzzle is just a position with a forcing answer, so the solver treats it like any other. Two signs tell you the puzzle is solved rather than merely evaluated. The first is a mate score, written M3 for mate in three: that is a proof, not an estimate. The second is a large gap between the best move and the second best. When the top move is two pawns better than the alternative, the puzzle has exactly one answer and the solver has found it.
When all three moves land within about 0.3 of each other, there is nothing to solve. The position is quiet and any of them is playable.
What a solver cannot do
A solver answers the position in front of it and nothing else. It will not tell you why you reached a position where the answer was hard to see, and that is the part that decides games. The players who improve fastest guess first and solve second, then look at the gap.
The gap is also the only thing worth measuring. One solved position tells you nothing about your play; thirty games sort into patterns. Chess DNA groups your mistakes into nine weakness themes, missed forks and pins and back rank weakness among them, so the repeat offender becomes visible instead of hiding one game at a time.
How deep does it solve?
Depth is how many half moves ahead the engine searches before it commits to an answer. Depth 10 is quick and already stronger than almost every club player. Depth 18, the setting Chess DNA uses when it analyses your imported games, is far more reliable in sharp tactical positions but takes noticeably longer in a browser tab. Start at the balanced setting and raise it when the position is unclear.
The engine is Stockfish 17.1, the same open source engine that powers analysis on Lichess and inside Chess DNA. It runs as WebAssembly in your own browser, so your position is never uploaded anywhere. The first search downloads roughly 7 MB of engine; after that it is cached and every later search starts instantly.
Frequently Asked Questions
Is this chess solver free?
Yes. The engine runs in your own browser rather than on a server, so there is nothing to charge for and no account to create. There is no cap on how many positions you solve.
Can it solve chess puzzles?
Yes. Set up the puzzle position, set the side to move, and solve. A mate is reported as M followed by the number of moves, for example M3 for mate in three, and that result is a proof rather than an estimate.
Does it solve a whole game or one position?
This page solves one position at a time. To have every move of a full game checked at once, paste the PGN into the free game review, which reports the accuracy for both players and the move that decided the game.
Is chess solved?
No. Chess has roughly 10 to the power of 44 legal positions, far beyond what any computer can enumerate. Endgames with seven pieces or fewer are solved exactly and stored in tablebases; everything above that is searched, not solved, which is why an engine returns an evaluation rather than a verdict.
Do I need to install anything?
No. The engine is WebAssembly and downloads on the first solve, roughly 7 MB, then stays cached in your browser. No position ever leaves your device.
