V4 adds 3x3 and 5x5 boards, match modes, replay, a mini shared notes section, optional computer player, confetti, and a help section. The full latest state still travels in the URL hash.
Open the page, set player names, and choose whether you want 3x3 or 5x5. Then copy the X link for one player and the O link for the other player.
Every move updates the URL hash. After making a move, the current player shares the updated link. The other player opens that new link and continues.
X link lets only X play on X turns. O link lets only O play on O turns. Spectator link is watch-only mode.
In 3x3, three in a row wins. In 5x5, four in a row wins. The game checks horizontal, vertical, and diagonal lines.
Free Play keeps going round after round. Best of 3 and Best of 5 stop when a player reaches the required wins.
If Computer O is enabled, O will automatically make a move after X plays. This works best when O is meant to be controlled by the page instead of a person.
The Replay Round button replays the current round move by move using the saved move history.
Send this to the X player.
Send this to the O player.
Watch-only mode.