Drop a disc
Tap any cell of a column and your cyan disc falls to its lowest empty slot. On a keyboard, press 1–7 to aim for a column.
Mini Games
Play Connect Four vs AI
Drop your cyan discs, the AI answers in amber, and the first to line up four in a row wins. The AI thinks behind the scenes on your device — so the board never stutters.
How it works
The AI answers
The AI searches the position on your device inside a background worker. It blocks your threats and stacks its own amber discs toward a winning line.
Four in a row wins
Link four discs horizontally, vertically, or diagonally first and the round is yours. If the board fills with no four, it's a draw.
Frequently asked questions
How do you win at Connect Four?
Connect four of your discs in a row — horizontally, vertically, or on a diagonal — before the AI does. You also want to block your opponent from reaching four while you build.
Is the Connect Four AI unbeatable?
No — it is strong but not solved-perfect. It always blocks a direct four-in-a-row threat and builds its own columns, but you can still beat it by creating two threats at the same time.
Why can't I drop a disc into a full column?
Discs stack from the bottom of each column. Once a column has six discs it is full, and neither player can drop another one there — that is the classic rule.
Why does the AI pause before moving?
The AI is searching the board on your own device inside a background Web Worker. That keeps the page responsive while it thinks — hence the short pause before each reply.
Does this game send my board anywhere?
No. Every disc and every AI move happens in your browser, and the AI's search runs locally too. There is no account and no server involved.