A Tic-Tac-Toe game that grows with every win

Start with the familiar three-by-three grid, then work through a strategy challenge that expands to boards as large as nine by nine. ANTB Tic-Tac-Toe has 20 computer levels, changing board rules and blocked squares, plus a two-player mode for taking turns on one device. It runs directly in your browser and needs no download.

How to play

Choose an open square to place your mark. In computer mode, you play as X against the computer; make the required line of marks before the board fills. Depending on the level, a line can be longer than three marks and some squares are blocked. Blocked squares cannot be used and interrupt a line. Their positions change between rounds.

Use the level selector to return to levels you have unlocked. Win a level to open the next one and collect its star. The computer becomes more challenging as you advance. Draws and losses do not unlock the next level, so try a different opening or use Hint to highlight a promising square.

Play with another person on the same device

Select 2 Players to take turns locally. Both players use the same board, alternating X and O. This mode opens every board size, making it a quick pass-and-play option for a friend beside you. To play online, select Online match and sign in. ANTB pairs you with another signed-in player in a classic three-by-three match; moves are checked by the server so both browsers stay in sync.

Tips for winning Tic-Tac-Toe

On a three-by-three board, take the centre when it is available; it is part of four possible winning lines.
Look for a move that creates two winning threats at once, and block your opponent when they are one mark from a line.
On larger boards, plan around the required line length and blocked squares rather than focusing only on the nearest open space.
Use the arrow keys and Enter to navigate and play. Press N for a new round, H for a hint, and T to switch between modern and retro styles.

Private, no-download browser play

The game runs in your browser and does not upload files. An account is not needed for computer or same-device play. Online matches require sign-in; the live board and player names are held temporarily to connect and synchronize the match. Your style and computer-level progress are saved locally in your browser. Clear this browser’s site data to remove that local progress.