How to play tic tac toe
- Choose your opponent: the computer (pick a level and who goes first) or a friend on the same device.
- Under "Rules and options" you can pick the board: classic 3×3, 4×4, 5×5 (four in a row) or Ultimate.
- Tap an empty square to place your mark. X always moves first.
- The first player to line up three marks (four on the bigger boards) horizontally, vertically or diagonally wins. If the board fills up with no line, it's a draw.
Tic tac toe tips and versions
On the classic 3×3 board, a game with perfect play from both sides always ends in a draw. If you go first, open in a corner or the center; if your opponent starts, take the center or a corner, and always block their line of two. To win, you need to create two threats at once.
The 4×4 and 5×5 boards need four in a row and leave more room for setting traps. Ultimate has nine small boards inside one big board: your move inside a small board decides which small board your opponent must play in, and to win you need to take three small boards in a row.
The easy level makes mistakes on purpose, medium looks a few moves ahead and hard never slips up on the 3×3. Everything is calculated on your device and nothing is sent to any server.
Good to know
- In Ultimate, if the small board you are sent to is already won or full, you can play in any open small board. If all the small boards are finished without a line of three, the player who won more small boards wins.
- Scores and settings are saved only in this browser: if you clear the site data, they are lost.
- Against the computer, Undo takes back your move and its reply; in 2-player mode it takes back the last move.
Frequently asked questions
How do you win at tic tac toe?
By lining up three of your own marks in a row horizontally, vertically or diagonally (four on the 4×4 and 5×5 boards). If the board fills up with no line, it's a draw.
Can you beat the computer on the 3×3 board?
Not on the hard level: it plays perfectly, and the best you can get is a draw. On the easy and medium levels you can beat it.
What is ultimate tic tac toe?
It's a version with nine 3×3 boards inside one big 3×3 board. The square you pick in a small board decides which board your opponent must play in. The winner is the first to take three small boards in a row.
Can I play with a friend on the same phone?
Yes. Choose the "2 players" mode and take turns tapping the squares.
Is it free? Do I need to install anything?
It's free, needs no sign-up and runs right in your browser, on phone, tablet or computer.