Play this position against the computer
选择白方和黑方的布局（或保留当前显示的），与电脑对弈。计算在你的浏览器中进行，不会向任何地方发送数据。
编号 0–959。双方编号相同就是常规对局；编号不同则双方各用自己的布局。
How strong is it, honestly
Two opponents answer here, and the page always says which one. The real one is Stockfish 19 Lite compiled to WebAssembly — the same engine that analyses games at the top level, running in your browser. You choose its strength next to the board, from about 800 to 2000, so that a beginner gets a game rather than a demolition.
Stockfish is 1.2 MB over the wire, so it loads when a game begins: here, with the first move (yours or, if you play Black, the computer's); on the home page the game starts by itself as soon as the page loads, so there it loads at once. Until it is ready, a small engine built into the site answers: it is far weaker, but it replies instantly. The rules are the same for both and are not theirs: moves, Chess960 castling, check and the end of the game come from the rules library that drives the board here and the Android app.
Everything is computed in your browser. No position and no move leaves this page.
Stockfish is free software under the GPLv3; its source is at github.com/official-stockfish/Stockfish, the WebAssembly build at github.com/nmrugg/stockfish.js. CH960 is GPLv3 as well.
Where to go next
Encyclopedia of balanced pairs
For a real opponent — people or a full engine with mentors — there is the Android app.在浏览器或 Android 应用中。无需安装 · 免费，无广告