A Field Guide to the Position

Rate every move.
Not just one.

Click any piece on Chess.com or Lichess and see every legal move it can make, ranked and color-coded by Stockfish 18, built to help you understand chess, not just play it.

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StockFishy analyzing a chess position on Lichess, showing top moves, ratings, and a predicted reply

Field Notes

Everything the engine shows you

Most tools hand you a single "best move" and leave the rest unexplained. StockFishy annotates the whole position, piece by piece.

I.

Every legal move, rated

Click any piece to reveal all of its legal moves at once, each ranked and color-coded on a six-step scale from Best down to Blunder, the same vocabulary used on Chess.com and Lichess.

II.

A board-wide overview

Before you click anything, every piece that can move is marked with a quiet ring and its own rating badge, and the three strongest moves on the whole board are drawn as arrows.

III.

A preview of the reply

A dashed arrow shows the response Stockfish expects from your opponent after the top move, a small look ahead, not just a single ply.

IV.

Continuous analysis

Toggle it on and the position re-analyzes itself after every move, yours and your opponent's, with nothing left to click.

V.

Runs on your machine

Stockfish 18 is compiled to WebAssembly and runs entirely inside your browser. No position, no move, no game is ever sent to a server.

VI.

A keyboard shortcut

Alt+A (Option+A on a Mac) triggers analysis without reaching for the mouse, useful mid-game on either site.

The Rating Scale

Six shades of judgment

Every move is classified relative to the position's best option, so a glance at the color tells you as much as the number.

Best Excellent Good Inaccuracy Mistake Blunder
Each move also shows a raw score. A plus number favors whoever's about to move, measured in pawns, so +1.2 is a modest edge and +4.0 is close to winning. A minus number favors the opponent instead. M3 means a forced mate in three moves; M-3 means walking into mate in three if the opponent finds the best defense.
A free account is required. StockFishy signs in with Google so your daily analysis limit can travel with your account rather than your browser. Sign-in happens once, from the extension's toolbar icon. The free plan includes 50 analyzed positions a day.

Free to start, 50 positions a day

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