Chess analysis through branching exploration.
Every different move creates a new branch. Navigate freely between variations — the full history of your exploration is preserved.
Stockfish 18 running at full strength in your browser. Ask for the best move for either side at any time — highlighted on the board with evaluation.
See every explored line as a clickable, zoomable tree. Green path shows where you are. Click any node to jump there instantly.
Drag pieces from the tray to set up any position. Floating panels for board, moves, and menu. Full-strength Stockfish best-move analysis, or import games and studies from Lichess.
Everything you need to explore, annotate, and study the game.
Click-to-move or drag-and-drop. Drag pieces from the tray to place them on the board. Arrow key navigation with Tab focus. En passant supported for manual moves.
171 openings shown as ghost branches in the tree. Win/draw/loss stats from master games. Click any opening to jump straight to that position.
Right-click nodes to mark moves as good (!), brilliant (!!), mistake (?), or blunder (??). Double-click to write notes. Color-coded in the tree.
Syzygy tablebases activate at 7 or fewer pieces. Perfect play — every move rated as win, draw, or loss with distance to zeroing.
Share full games with branches via URL link. Browse the study library for curated openings and classic games. Export PGN with variations, import from Lichess, or save locally.
The full-screen tree is the default view. Board, piece tray, and moves panel float as draggable, resizable panels. Zoom with scroll wheel or slider, pan by dragging.
Board rotated 90 degrees for side-by-side play. Flip to swap white and black sides. Toggle between 1P and 2P modes.
Piece tray beside the board shows all pieces with captured counts. Drag pieces from the tray onto the board to create any position.
One click to see the engine's top recommendation highlighted on the board with centipawn evaluation. Full-strength Stockfish analysis.
Paste Lichess game or study URLs to load with full variations. Open the study library for curated games. Import PGN with Ctrl+V. Type moves directly in the move list.
Classic brown board or Bang Labs dark theme with indigo accents, themed tree colors, and fireworks on checkmate (Bang Labs only). Persists across sessions.