Chess Analysis Board

The ChessDream analysis board is a free online chess engine you can use without an account. Set up any position, paste a FEN or a PGN, or import a game from Chess.com or Lichess, and Stockfish 16+ evaluates the position directly in your browser. You get a live evaluation, the engine's best lines several moves deep, and a move-by-move breakdown with each move classified as brilliant, best, inaccuracy, mistake, or blunder. Nothing is capped and nothing is stored on a server.

Why the engine runs in your browser

Stockfish is compiled to WebAssembly and runs on your own device rather than on a server. Two things follow from that. Your games never leave your browser, so there is no upload and nothing to delete afterwards. And because you are using your own processor rather than sharing a queue, there is no per-user quota to enforce, which is why the analysis is unlimited instead of capped at one game a day.

The practical trade-off is that analysis speed depends on your device. A higher depth setting searches further ahead and gives a more reliable evaluation, but takes longer. For reviewing a full game, the default depth is usually enough to find every blunder and missed win; raise it when you want to settle a specific critical position.

How to analyze a chess game

1. Paste your PGN or import a game by username, or play out a position on the board.
2. Pick an analysis depth — higher depth is more accurate but slower.
3. Run the analysis; Stockfish evaluates every move in the game.
4. Review the move list to see where the game turned and what the engine preferred.
5. Study the suggested best lines and carry the lesson into your next game.

Move classifications explained

ChessDream labels each move by how much it changes the engine's evaluation (measured in centipawns, where 100 centipawns ≈ one pawn):

• Brilliant: a strong, often hard-to-find move that is also a sacrifice or only-move.
• Best: matches the engine's top choice for the position.
• Inaccuracy: a small slip that loses a little evaluation but rarely the game.
• Mistake: a clearer error that hands the opponent a meaningful edge.
• Blunder: a serious error that can swing or lose the game.

Frequently asked questions

Is the analysis really free?

Yes. Analysis is unlimited and free, with no account required. Unlike platforms that cap free users to one game review per day, ChessDream has no daily limit.

Does my game data leave my device?

No. Stockfish runs locally in your browser via WebAssembly, so the analysis happens on your device — there is no cloud round-trip for the engine evaluation.

Can I analyze a single position?

Yes. Use the FEN position analyzer to evaluate any position from a FEN string, or study openings in the opening study tool.