Connect Four vs Computer

Connect Four vs Computer is a free online board game you can play instantly in your browser against a computer opponent named Otto, no download, no account, and no waiting for another player. Play on the classic 7-column by 6-row grid: choose a column, drop your red disc, and it falls to the lowest open space. The first side to connect four discs horizontally, vertically, or diagonally wins. Play through 15 levels that make Otto stronger with every match, from loose random drops early on to deeper look-ahead and tighter blocking near the final grid. Win a level to unlock the next opponent strength; Try Again starts a fresh match at the same difficulty.

How to play Connect Four vs Computer

1. Choose any open column on the 7x6 board to drop one of your red discs into it.
2. Your disc falls to the lowest empty space in that column, so every move changes what can be supported above it.
3. Otto, the computer opponent, drops a yellow disc after your move unless the game has already ended.
4. Win by connecting four of your discs in a straight line horizontally, vertically, or diagonally.
5. If all 42 spaces fill without either side connecting four, the match is a draw and you can replay the level.
6. Clear a level to unlock the next one, where Otto reads farther ahead and blocks more dangerous threats.

Tips

• Start near the center when you can — center columns participate in more horizontal and diagonal winning lines than edge columns.
• Always check whether Otto has three in a row with an open fourth space before you attack; blocking an immediate loss comes first.
• Build threats that work in two directions at once, such as a horizontal three that also supports a diagonal, so Otto cannot block everything with one drop.
• Avoid placing a disc that gives Otto the exact support square needed to complete a diagonal on the next turn.

FAQ