Licenses

Positions missing from the games database are evaluated by the Stockfish chess engine running directly in your browser. The engine is distributed under the GNU General Public License version 3 (GPLv3) and is used without modification.

© 2026 The Stockfish developers (see AUTHORS file).
WebAssembly build: stockfish.js © Chess.com, LLC.
Evaluation network: nn-9067e33176e, © Linmiao Xu (linrock).

Source code: github.com/official-stockfish/Stockfish, build — github.com/nmrugg/stockfish.js.

Full license text: GPLv3.

Move statistics are built from the open Lichess games database (CC0) and the open lichess/chess-openings dataset (CC0).