Chess analysis through branching exploration.
Every different move creates a new branch. Navigate freely between variations — the full history of your exploration is preserved.
Same position, same response. Play a different move and Stockfish picks fresh from its top 5 — weighted by score, cached by FEN.
See every explored line as a clickable, zoomable tree. Green path shows where you are. Click any node to jump there instantly.
Set up any position, adjust engine strength, pause the engine to input games manually, show the best move with evaluation, or import directly from Lichess.
Everything you need to explore, annotate, and study the game.
Click-to-move or drag-and-drop. Free piece placement for analysis. Board labels outside the squares. 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.
Stockfish 18 with adjustable Skill Level (0-20), think time, and temperature. Blue-to-red slider. Auto-responds — click a piece to interrupt.
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.
Double-click to expand the game tree to full screen with a floating draggable board. Zoom with scroll wheel, 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.
Place pieces freely to create any position. Select from the palette, toggle sides, and start playing.
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. Persists across sessions.