4Fever
Drop discs and line up four in a row.
Your move (red)
Runs entirely in your browser — no signup, and your scores stay on your device.
About this game
Take turns dropping discs down the columns of a seven-wide, six-tall grid; a disc falls to the lowest free slot. Be the first to line up four of your colour in a row — across, up, or on either diagonal. The computer opponent uses an alpha-beta minimax search that looks several moves ahead, weighing threats and blocks, so higher difficulties are genuinely tough. You can pick the level and who goes first.
Strategy
Play the centre column early — its discs take part in the most possible fours. Watch the AI: if it gets three in a row with an open end, block immediately. Your own goal is a 'double threat' — two ways to complete four on the next move, so a single block can't stop both.
How to play
- 1Pick a difficulty and who moves first.
- 2Click a column to drop your (red) disc into it.
- 3The computer (amber) responds after a moment.
- 4Get four of your discs in a row — any direction — to win.
Controls
- Click / TapDrop a disc in that column
- New gameReset the board
Features
- Alpha-beta minimax AI that reads several moves ahead on Medium and Hard.
- Three difficulty levels, and you decide who drops first.
- Highlights the winning four, with a running win/draw/loss tally.
Frequently asked questions
How strong is the AI?
On Hard it searches six moves ahead with alpha-beta pruning and a position heuristic that values central play and blocks your threats, so it plays a strong tactical game. Drop to Easy or Medium for a gentler opponent.
Who goes first?
Your choice — toggle between you and the computer. Moving first is a genuine advantage here, so it's the harder side to hold off.