Stockfish.js 19.0.0 — lite single-threaded WASM build

Stockfish.js 19 (c) 2026, Chess.com, LLC
Based on Stockfish (c) T. Romstad, M. Costalba, J. Kiiski, G. Linscott and other contributors.
Licensed under the GNU General Public License, version 3. See COPYING.txt.
The WASM engine file is distributed without modification.
The JavaScript loader was modified by lookchess on 2026-10-15 under GPLv3:
- Remove the recursive stream read error callback (upstream issue #120 / PR #122).
- Report failed WASM loading through Worker.onerror instead of an unhandled Promise rejection.
The complete local patch source is distributed alongside this notice as patch-engine-loader.mjs.
To reproduce, apply its patchEngineLoader function to the original v19.0.0 JavaScript binary below.
Upstream report: https://github.com/nmrugg/stockfish.js/issues/120
Upstream proposed fix: https://github.com/nmrugg/stockfish.js/pull/122

Matching source release and build instructions:
https://github.com/nmrugg/stockfish.js/tree/v19.0.0
Corresponding source archive:
https://github.com/nmrugg/stockfish.js/archive/refs/tags/v19.0.0.tar.gz
Release binaries:
https://github.com/nmrugg/stockfish.js/releases/tag/v19.0.0
Authors:
https://github.com/nmrugg/stockfish.js/blob/v19.0.0/AUTHORS

The lite build is a smaller, weaker engine than the full Stockfish build.

Chess rules: chess.js 1.4.0 (c) 2025 Jeff Hlywa, BSD-2-Clause.
See CHESS-JS-LICENSE.txt. Source: https://github.com/jhlywa/chess.js/tree/v1.4.0