Paste a PGN for move-by-move Stockfish analysis, solve a daily puzzle, or replay a position you blundered.
/chess-trainer/?fen=…&best=…&yourMove=…This is a free chess trainer with four modes. Analyze Game takes any PGN — paste from chess.com, Lichess, or anywhere else — and runs Stockfish locally in your browser to grade every move with centipawn loss, classify mistakes (inaccuracy / mistake / blunder), and show the top engine variations. Daily Puzzle pulls the current Lichess daily puzzle and lets you solve it move by move with instant feedback. Skill Drills lets you pick a specific skill to work on — mate finding, winning material, forcing moves, piece safety, defensive vision, or trade evaluation — and drill real positions with engine-graded feedback and a written explanation of why each move works or fails. Replay Trainer takes a position you previously got wrong (loaded via URL parameters) and lets you try the move again.
Each skill bucket contains 10 positions curated from real games where that specific pattern was missed. You see the board, try a move, and the engine evaluates centipawn loss vs. the best move. More than just right/wrong — you get a written explanation of the principle behind the pattern, so the lesson transfers to future games.
Reviewing the games you played — especially the losses — is the single highest-leverage chess study activity at the club level. Every game has a moment where the evaluation flipped; finding that move and understanding why it was wrong builds the pattern recognition that separates 1200-rated players from 1800-rated ones.
Stockfish runs entirely in your browser as a Web Worker — no PGN data is sent to our servers. Analysis depth defaults to 16 ply and adjusts based on time control. The board and move generation use chess.js. Daily puzzles come from the public Lichess Puzzle API.
Use the ← and → arrow keys to step through moves. Click any move in the right sidebar to jump to that position. The eval bar on the left of the board shows the current evaluation from White's perspective; centered means equal.
Practice chess positions and improve your tactical skills. Drill specific patterns like forks, pins, and skewers from positions drawn from real games to build pattern recognition.
Focus on tactics training for 15-20 minutes daily. Pattern recognition from solving positions is the fastest way to improve at the beginner and intermediate level.
Start with basic checkmate patterns, then move to forks and pins. These fundamental tactics appear in nearly every game and give the biggest rating improvement.