Drop discs to connect four in a row — horizontally, vertically, or diagonally. Play against the computer or a friend on the same device.
🔴 Connect Four
Drop discs to connect 4 in a row — horizontal, vertical, or diagonal!
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Register Free 🚀About Connect Four
Drop discs into a seven-column, six-row grid and try to line up four in a row — horizontally, vertically or diagonally. Gravity is the whole game: you choose a column, not a square, and every disc you play also decides what the square above it becomes.
The centre column is worth more than the others
A disc in the middle column can be part of more four-in-a-rows than a disc anywhere else, and the count falls off sharply toward the edges. Taking and holding the centre is the closest thing Connect Four has to a universal opening principle.
It is also why the first player has a real advantage. Connect Four was solved by computer in 1988: with perfect play, the player who moves first wins by starting in the centre column. Any other opening move loses or draws against perfect defence.
Think in pairs of rows, not single squares
Because discs stack, playing a square gives your opponent the square directly above it. This is the central tactical idea of the game: never create a threat that hands your opponent a winning square as a side effect.
Experienced players count parity. On a six-row board, threats that complete on an odd row tend to favour the first player and threats on an even row the second, because of whose turn it will be when that row fills. You do not need the full theory to benefit — just get into the habit of asking what your move gives away above it.
Build two threats at once
A single line of three is easy to block. Two lines of three that complete in different columns cannot both be blocked, and that double threat is how nearly every game between decent players is won.
The most common form is a horizontal three with open ends on both sides, so either end wins. Watch for it in your own position and, more importantly, in your opponent's — spotting a developing fork one move before it closes is the single most valuable defensive skill here.
How the computer plays
The CPU searches five moves ahead using minimax with alpha-beta pruning, which means it evaluates the position that results from every reasonable line of play and picks the best. At that depth it will not miss an immediate win, will not allow one, and will usually see a double threat before it forms.
It is beatable but it does not blunder, so wins come from long-range planning rather than hoping it misses something. If you want a gentler start, Tic-Tac-Toe at cerdikcerdik.com/games/tic-tac-toe uses the same threat-and-block ideas on a much smaller board.
Frequently asked questions
Does the first player always win at Connect Four?
With perfect play, yes — the game was solved in 1988 and the first player wins by opening in the centre column. Perfect play means never erring across the whole game, which is why real games remain competitive.
What is the best opening move?
The centre column, without close competition. It participates in more possible four-in-a-rows than any other column and denies the same advantage to your opponent.
How strong is the computer opponent?
It looks five moves ahead, so it will never miss a win or fail to block one, and it usually sees double threats forming. Beating it requires a plan rather than a trap.
Can I play against another person?
Yes — pass-and-play on one device is supported, so two people can share a phone or tablet.