Yes, completely free with no signup or ads.

Does my data leave my device?

No. Win/draw/loss counts are stored only in your browser's localStorage.

Does it work on mobile?

Yes. Tap any cell to place your mark on iOS Safari and Android Chrome.

在 3×3 棋盤上挑戰無敵 AI 對手的 X 與 O 對決。

You (X)

Draws

AI (O)

Your turn (X)

You are X and move first. Click or tap any empty cell to place your mark.
The AI responds immediately with the optimal O move using the minimax algorithm.
First to align three marks in a row, column, or diagonal wins. If the board fills with no winner, it's a draw.

Is it free?: Yes, completely free with no signup or ads.
Does my data leave my device?: No. Win/draw/loss counts are stored only in your browser's localStorage.
Does it work on mobile?: Yes. Tap any cell to place your mark on iOS Safari and Android Chrome.

Last updated: 2026-05-20 By jarvisbox