Connect 4 Online

Play Connect 4 in your browser—no download, no sign-up. Drop discs to get four in a row. Play against the computer on easy, medium, or hard.

What is Connect 4?

Connect 4 is a two-player game played on a vertical board with 7 columns and 6 rows. Players take turns dropping colored discs into columns. The discs fall to the lowest empty slot in that column. The first player to get four of their discs in a row—horizontally, vertically, or diagonally—wins.

In this version you play as red against the computer (yellow). The computer uses a minimax algorithm with alpha–beta pruning, so harder difficulties look ahead more moves.

How to Play Connect 4

• Click a column to drop your disc. Your disc (red) falls to the lowest empty row in that column.
• The computer (yellow) then plays automatically after a short delay.
• Win condition: Be the first to get four of your color in a row—horizontal, vertical, or diagonal.
• Draw: If the board fills up with no four in a row, the game is a draw.

You can only drop in columns that are not full. Hover over a column to see it highlighted before you click.

Difficulty Levels Explained

• Easy – The computer looks ahead 2 moves and sometimes plays randomly. Good for learning and relaxed play.
• Medium – The computer looks ahead 4 moves. It will block obvious wins and set up threats.
• Hard – The computer looks ahead 6 moves. It is much stronger and will rarely miss a win or block.

Higher difficulties use the same board and rules; only the computer’s search depth and strategy change.

Tips & Strategies

1. Control the center. The middle column (column 4) gives the most options for horizontal, vertical, and diagonal lines.
2. Build two at once. Try to create positions where you have two ways to complete four in a row so the computer can’t block both.
3. Block the computer. If the computer has three in a row with an empty space, play in that space to block.
4. Watch the diagonals. Many wins come from diagonals; they’re easy to miss until it’s too late.
5. Don’t help the computer. Avoid dropping under a column where the computer could complete a line on the next move.

Why Play Connect 4 Online?

Playing Connect 4 in the browser is quick and convenient: no install, no account, and it works on any device. You can play a fast game against the computer on a break or challenge yourself on hard when you have more time. Whether you’re new to the game or brushing up on strategy, Connect 4 online is an easy way to play anytime.