Play this position against the computer
Chess960 setup 489. The computer runs in your browser — nothing is sent anywhere.
Levels from 1400 up are the engine’s own strength limiter. Below it the limiter does not work — Stockfish silently clamps anything under 1320 to its minimum — so the weaker levels are made another way, and their numbers come from measured matches, not from a wish. Treat them as approximate.
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. Its strength is deliberately capped so that a beginner has a game rather than a demolition: fast ≈ 1320 Elo, normal ≈ 1600, longer ≈ 2200.
Stockfish is 1.2 MB over the wire, so it loads only when you start a game — not for everyone who opens the page. 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
About this setup · Encyclopedia of balanced pairs
For a real opponent — people or a full engine with mentors — there is the Android app.In your browser or in the Android app. Nothing to install · Free, no ads