Tic Tac Toe - Play Online vs Computer or Friend
Play Tic Tac Toe online against an unbeatable AI (Minimax algorithm) or a friend. Track wins, losses, and draws with score history.
About this calculator
Play Tic Tac Toe against a friend or the computer at easy or unbeatable level, and track wins, losses and draws.
Simple, quick and a nice look at game theory.
How to use it
- Choose 2 players, Easy or Hard.
- Click a square to place your mark.
- Press New Game to play again.
Strategy
With perfect play from both sides, Tic Tac Toe always ends in a draw. The hard AI uses minimax, which explores every possible continuation and picks the move with the best guaranteed outcome, so you can't beat it. If you go first, take a corner (or the centre); if the opponent starts in a corner, take the centre. Look for forks: moves that create two winning threats at once.
Worked example
Total positions
| Possible games | 255,168 |
| Outcomes with perfect play | Draw |
Tips and common mistakes
- Take the centre or a corner first.
- Block the opponent's two-in-a-row.
- Create forks.
- Don't open on an edge.
- Try Easy mode to practise forks.
Frequently asked questions
Can I win against the hard AI?
No, the best you can do is draw.
What is minimax?
An algorithm that picks moves assuming best play.
Who wins with perfect play?
Nobody; it's a draw.
Best first move?
A corner or the centre.
Is it free?
Yes.
Is my score saved?
Only in this session.