Full legal rules — castling, en passant, promotion, check, checkmate. Take on the computer, hand the device to a friend, or send a friend a link and play them from wherever they are. Any position can be sent on as a plain link too. No account, nothing to install.
Black
White
White to move
Game on — good luck.
Mode
Two players means two people at this one device, taking turns on the same board. Play a friend is the online version of that, and it has worked since 5 August 2026: you send someone a link, and each move travels through our relay — the /relay endpoint on this same domain — which pairs the two browsers and copies the move across. That relay holds no account, no game and no history: when either tab closes, or when the relay process itself restarts, the relay session ends and nothing re-pairs the two of you automatically. Your board is not lost with it — the position stays in this tab, and the resume link further down starts it again as a fresh game with the same colours, once you send that link across. Chat is a separate path and does not go through it — your messages run browser-to-browser, so each player’s browser learns the other’s IP address, while the relay sees which two addresses paired and when, but never a word of what you type.
Play a friend online
Read this before you press the button. This is the one mode that leaves your device. Each move goes to /relay on this domain, a small process we run that pairs two browsers by a random game id and copies the moves across; it decodes nothing and stores nothing, but it does see which two addresses paired and when. Chat is different: it goes straight to the other browser, which means each of you learns the other’s IP address — fine for a friend you sent the link to, a bad trade with a stranger — and because nobody but the two of you can see those messages, nobody moderates them either. If either tab closes, or the relay restarts, the relay session ends where it stood and nothing re-pairs you automatically — there is no rejoining that session, and the relay kept nothing to rejoin. Your own board survives that: it stays in this tab, and the resume link on this page starts a fresh game from the same position. Two players and vs Computer never open the socket at all.
Chat with your opponent
No messages yet.
Where these messages go. A message you send here goes straight to the other player’s
browser over a WebRTC data channel — it does not take the relay path your moves take.
Your moves do go through our relay, every one of them. Two honest caveats, neither of which we can
remove: setting that channel up needs one offer and one answer passed between the two tabs, and the
only thing they share at that point is the relay socket, so the relay still sees which two
addresses paired and when — never a word of what you type. And a direct connection means
each player’s browser learns the other’s IP address; that is how peer-to-peer
works everywhere, it is why there is no public matchmaking here, and it is a fair trade with someone
you already sent a link to. There is no TURN server, so no third party carries your messages; one
outside machine is involved, the public STUN server stun.l.google.com:19302, and its
whole job is to tell your browser what its own address looks like from the internet. Nothing is
kept: no transcript, no history, nothing written to this device, and closing either tab ends it.
Play as
Computer strength
Position & game record
Copy share link (under the board) puts the position — and the moves that led to it, if they fit — after the # in the URL. Browsers never send that part of a URL, so it travels inside the link itself and is not in anyone's request log. Whoever opens it sees exactly this board.
This tab already keeps the game you are playing: reload it, or come back after your phone locks the screen, and the board is exactly where you left it. That copy lives in this tab’s own history entry — not in site storage, and it does not reach a second tab, another browser or another device. The resume link does: unlike the share link above it also carries who plays which colour, so whoever opens it is seated on the side the link names, on the position the link names. It is a fresh board for two people, not a reconnection: the relay session behind a friend game is gone the moment either tab closes, and nothing re-pairs you automatically, so opening this link is you two starting a new game on the position the old one stopped at — the relay had kept nothing to give back.
Moves
No moves yet — White starts.
Click a piece to see its legal moves, then click a square — or just drag it.