What you can do here
Play chess against a local AI with four strengths, pass one device for two-player, or open a room with a link for someone on another device.
Where games are stored
Human-vs-AI and two-player progress stay in this browser. Clearing site data removes them. There is no account to create.
What this table is not
It is not a rating list, a titled-coach service, or a stranger matchmaking lobby. Engine strength varies with the device and the level you pick.
Local Stockfish AI
Every vs-AI level and every hint runs Stockfish with NNUE evaluation inside your browser (lite single-thread WebAssembly). Nothing is sent to a cloud chess server for the move search. Strength is adjusted with Stockfish skill settings and think time. It is for practice, not a FIDE rating or coaching service.
Open-source credits and sources
Human-vs-AI play uses the open-source Stockfish chess engine and the stockfish.js browser packaging. Upstream projects and authors do not endorse this site.
Corresponding source for the engine and the WASM packaging is available from the projects linked below. This site ships the public Stockfish.js 18 lite-single release under the GNU GPL v3; licence text is also kept at /brand/chess/stockfish/COPYING with a short notice at NOTICE.md.
Stockfish — authors, source, GPLv3
Engine: github.com/official-stockfish/Stockfish. Authors include Tord Romstad, Marco Costalba, Joona Kiiski, Gary Linscott, and many contributors. Stockfish uses NNUE evaluation networks published with its releases.
Licence: GNU General Public License version 3. Full text: COPYING and gnu.org/licenses/gpl-3.0.html.
stockfish.js — browser WASM packaging
Packaging used here: github.com/nmrugg/stockfish.js (Stockfish.js 18 lite single-thread build). Copyright Chess.com, LLC and contributors (including Nathan Rugg). Also under GPLv3; see the same COPYING file.
About Ply Yard
This board is maintained by Ply Yard. Other studio boards are separate sites. If something looks wrong on the board, or a room will not connect, write through Contact.