ChessLab

ChessLab is a complete chess companion: play, analyse, train and experiment, with the Stockfish engine built in and without ever leaving the app. Nothing is sent to a server.

OPPONENTS THAT PLAY LIKE PEOPLE
Nine characters played by Maia-3, a network trained on millions of human games: it does not look for the best move, it plays the one a human of that level would play — blunders included at the lower levels. Each has a style, an opening repertoire, a temperament and a portrait, and a level set on the human scale. Or face Stockfish itself, from beginner to full strength. With or without a clock: bullet, blitz, rapid, classical, with increment.

REALLY ANALYSE YOUR GAMES
Every move is graded — excellent, good, inaccuracy, mistake, blunder, missed chance — and each player gets an accuracy out of a hundred. The evaluation curve shows at a glance where the game turned.

Above all, the app tells you WHY a move was bad, in one sentence: "back-rank mate", "fork on your rook and your knight", "your bishop was hanging". This is not an invented explanation: the engine's refutation is replayed on a board, and only what can be seen there is named.

And what you missed becomes an exercise: the positions where you went wrong are filed next to the puzzles, to work on again.

Load a game by PGN, by FEN, from the position editor, or by photographing a board.

OPENINGS
58 openings written by hand, in English and French, all checked against the engine. Walk through them move by move: each move is explained, the alternatives are offered, and coloured arrows tie the board to the move list. Spaced repetition makes them stick.

THE ENDGAME CORNER
78 courses proved by tablebase — the exact mathematical verdict: no move taught throws away a win, no defence offered loses a draw. From the opposition to the famous studies.

PUZZLES
Over 100,000 tactical problems from the Lichess database, filtered by level and by theme — plus your own, drawn from your own mistakes.

VARIANTS
Twelve: Chess960 (Fischer Random), King of the Hill, Three-Check, Horde, Racing Kings, Atomic, Crazyhouse, Antichess, Barricades and its random version, Duck Chess and Stolen Move. Each is set up like a real game — side, engine strength, clock, assistance — and reviewed afterwards by the variant's own rules, not by ordinary chess ones.

TWO PLAYERS
Two people on one device, the board flipping each move so it reads right from both sides.

LABORATORY
Set two configurations against each other over a series of games to compare their strength.

SWITCH MODE WITHOUT LOSING YOUR PLACE
The position you are looking at travels to another mode at the touch of a button: a move intrigues you during an analysis, try it against the computer, then come back.

PRIVACY
No account, no server, no advertising, no analytics. The app does not even hold permission to reach the internet: your games and settings stay on your phone. To move to another device, a single file you write and reopen wherever you like.

English and French, interface and course content alike. Portrait and landscape.

ChessLab embeds the Stockfish engine (GPLv3), the Maia-3 network from the University of Toronto (AGPLv3) and the cburnett piece set (CC BY-SA 3.0). Puzzles come from the Lichess database (CC0).