Chess · the Chess course

Chess board

One board for everything. Analyse steps through a line with the engine's best moves and the opening book's moves on from each position; move a piece to try your own. Play the engine plays the board's position out against Stockfish and flags your blunders. Pick a line from Openings to learn it, or load one of your chess.com games to see every move graded.

The engine is Stockfish 19 (lite), compiled for browsers by stockfish.js and served from this site under the GNU General Public License v3; its source is at those links. It runs on your device and is downloaded once (about 2 MB). Opening names and lines come from Lichess's list of named openings (public domain). Games come from chess.com's published-data API, read straight from your browser only when you open your games; nothing is stored on this site's servers, and analyses are kept on this device. Grades follow chess.com's published bands, but chess.com also weighs the players' ratings and runs a stronger engine, so a grade here can differ, most often for brilliant and great moves.