Chee - Live Chess Analysis

Real-time Stockfish analysis on chess.com and lichess — eval, best moves, classifications, traps, and more

Chee adds a real-time analysis panel to your chess games on Chess.com and Lichess.org. It runs Stockfish (one of the strongest chess engines) entirely in your browser using WebAssembly — no server, no account, no data sent anywhere. Analysis: • Multi-line analysis — see the top 3–5 best moves and continuations • Adjustable search depth (15–22 ply) with optional wait-for-full-depth • Move classifications — Brilliant, Crazy, Best, Excellent, Good, Inaccuracy, Mistake, Blunder • Move guard — pick up a piece to see which destination squares are bad moves (! badges) • Tactical insights — dashed arrows show the best move after Mistakes and Blunders • Pre-move hints — see the engine's best move or classification-based hint arrows • Trap detection (Trapboy) — finds traps via sacrifice detection, tempting capture analysis, and a 10-trap opening database (Legal, Lasker, Noah's Ark, and more) • Crazy sacrifice detection — flags wild material sacrifices that maintain advantage • Book move detection with continuation arrows from ECO opening database Display: • Board preview — hover analysis line moves to see the predicted position on the board • Eval bar showing who's winning at a glance • Eval score chart — SVG area chart with hover tooltip tracking the game • Opening name display — 193-entry ECO opening database • Accuracy tracker — running accuracy percentage (chess.com-style formula) • Arrow overlays on the board for suggested moves Export & Debug: • PGN export — copy annotated PGN with eval comments, NAG codes, and player names • Copy FEN to clipboard with one click • Copy debug info — one-click diagnostic dump for troubleshooting UI: • Compact 2-column settings popup with section headers • Draggable panel — drag the header to reposition, double-click to reset • Resizable panel — drag the bottom-right grip to adjust width • Minimize or hide the panel (Alt+C keyboard shortcut) • Catppuccin theme system — Latte, Frappé, Macchiato, Mocha, or auto-match the site theme • All settings apply in real-time — no page reload needed Supported sites: • chess.com — live games (/game/*, /play/*) • chess.com — puzzles, rush, battle, learning (best move arrow, each togglable) • chess.com — daily chess (best move arrow, live-togglable) • lichess.org — all game pages • lichess.org — training, storm, racer, streak (best move arrow, each togglable) All analysis runs locally in your browser. No data is collected or transmitted.