Analysis Board
White to move
0.00
Level
Starting the engine…
- No lines yet.
Thinking time
Want moves graded rather than suggested? A Game Report classifies every move in a finished game.
Want moves graded rather than suggested? A Game Report classifies every move in a finished game.
The Analysis Board is a chess board with Stockfish 18 running beside it. Move a piece and the engine reads the new position straight away: an evaluation, a verdict in plain words such as "White is slightly better", and its three best lines written out in normal chess notation. It is free, it needs no account, and the engine runs in your browser, so there is nothing to install.
Paste a FEN to jump straight to a position, or paste a whole PGN and the game loads with its moves. From there you can play on, take moves back one at a time with Undo, turn the board round with Flip, or start again from the opening position with Reset. Copy FEN gives you the current position as a line of text you can save, share or paste into another tool.
If you want to set a position up by hand instead, build it in the Position Editor and send it here with one click.
The engine searches for its three best moves rather than one, so you see the alternatives next to the top choice, each with its own evaluation and continuation. That is usually more useful than a single best move: it shows whether the position has one move that holds or several that are close.
You choose how long it thinks: 3 seconds for a quick read, 6 seconds by default, or 12 seconds for a deeper search. A longer search goes further ahead and is steadier in sharp positions, and how deep it gets in that time depends on the device you are using.
Scores are given from White's side of the board. +1.00 is roughly a pawn's worth of advantage for White, a minus sign means Black is better, and M4 means mate in four. The words next to the number put the score into plain English, from Level through slightly and clearly better to winning, so you can read the position at a glance without doing the arithmetic.
The bar beside the board shows the same evaluation as a picture: the more of it is white, the better White stands. It reads the same way as the evaluation bar in a Game Report.
The board is for exploring: a position from a book, a line you want to test, the one moment in your own game you want to look at again. If you want a finished game graded move by move, with accuracy for both players and every move labelled from Brilliancy to Blunder, open it in the Game Report instead. If you only want the engine's answer for a single position, the Best Move Finder gives you that and nothing else.
Yes. There is no account, no card and no limit on how many positions you analyse.
Stockfish 18, running in your browser. It is the same engine the Lumichess Game Report uses.
Both. A FEN jumps to that position. A PGN loads the whole game with its moves, and you can take them back one at a time with Undo.
Three. You see the engine's best move and its next two choices, each with an evaluation and the moves that follow.
You choose: 3, 6 or 12 seconds. Six is the default. How deep it searches in that time depends on your device.