♚Open in the app

Play a friend from this position

Pick the pace, get a link — send it or let your friend scan the QR. You both play in the browser; nothing to install and nothing to sign up for.

Numbers from 0 to 959. The same number for both sides is the usual game; different numbers give each side its own setup.

Balance computed. The pair is in the encyclopedia of balanced pairs: |cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree.

Neither side starts better.

Pair 179–951: full analysis

What is Undo Chess?

How this works

The game runs on our server, and the clock is the server’s: both of you see the same time to the millisecond, and a slow connection cannot be turned into extra thinking time. Moves and castling — including the Chess960 kind, where the king takes its own rook — are judged by the same rules library that drives the app.

You play as a guest: no account, no email, no password. The link is the whole invitation, and it is good for fifteen minutes; if your friend has the Android app, the same link opens the game there instead — both sides speak the same protocol.

Any of the 960 starting setups works here, and so do asymmetric pairs, where White and Black start from different setups. Choose both numbers above: if the pair is in our database of balanced pairs, the page says so and shows its evaluation; if not, it warns that one side may start better.

Where to take a position from

All 960 setups · Encyclopedia of balanced pairs · Play the computer instead

Play Chess960 now

In your browser or in the Android app. Nothing to install · Free, no ads