Connect Four FAQ

Yes, completely free. No signup, no account, no download. Open the page and start playing immediately. No ads cover the board during a game.

No. Not for any mode. Pass and play, vs AI, and multiplayer with a friend all work without an account. We do not collect personal information.

Yes. The game is built mobile-first. Tap any column header or column number at the bottom to drop your piece. The board scales to fit your screen. Works on all modern smartphones and tablets in portrait and landscape.

Any modern browser - Chrome, Firefox, Safari, Edge. The game does not require any plugins. It uses standard HTML5, CSS, and JavaScript. Internet Explorer is not supported.

Pass and play and vs AI modes work fully offline once the page has loaded. The game logic runs entirely in your browser. Online multiplayer with a friend requires an active internet connection.

Visit the Play with Friends page. Click Create Game, copy the invite link, and send it to your friend by text, Discord, email, or wherever. When they open the link, both browsers connect peer-to-peer via WebRTC and the game starts. No account required on either side.

School and work firewalls sometimes block WebRTC, which the multiplayer feature uses to connect two browsers directly. Try switching to a mobile hotspot or a different Wi-Fi network. If both players are physically in the same location, use Pass and Play (same device) mode instead.

Yes. Both players can be on any device. The invite link works on phones, tablets, and desktops. Tap the column header to drop your piece.

No. We support invite-link multiplayer (you and a specific friend) but not random matchmaking with strangers. For public matchmaking, sites like Papergames.io and BoardGameArena have that feature.

Four levels: Easy (depth 2, misses some threats - good for kids), Medium (depth 5, blocks obvious threats), Hard (depth 8, strong positional play - beats most adults), Impossible (depth 12 minimax, approximates perfect play - will not lose from a winning position).

If you go first on Impossible and play the centre column, you have the theoretical advantage - Connect Four is solved in favour of the first player. With precise play following our strategy guide, you can beat the Impossible AI. If the AI goes first on Impossible, it is extremely difficult to win because the AI is approximating the known perfect-play solution.

The Hard AI searches 8 moves ahead. Moves that look suboptimal in the short term may be part of a deeper strategy that the AI can see and you cannot yet. These are deliberate - the AI is thinking further ahead than its apparent move suggests.

No. The AI runs entirely in your browser. No data is sent to our servers during a game. This is why it works offline.

Column 4 (the centre). The centre cell participates in 13 of the 69 possible winning lines - more than any other position. This is both a strong strategic principle and a result of the mathematical proof that the game is solved.

Yes. Victor Allis proved in 1988 that with perfect play, the first player always wins by opening in the centre column. James Allen independently confirmed this via brute-force computer search the same year. See our full explainer.

Yes. Four in a row diagonally counts in both directions - going up-right and going up-left.

If all 42 cells are filled and no player has four in a row, the game is a draw. Draws are relatively uncommon between evenly-matched players but do occur, particularly in games where both players play very defensively.

21 red and 21 yellow pieces, 42 total. The 7x6 board has exactly 42 cells.

Official box says 7+. Children as young as 5 can understand and play the game. The strategic depth rewards older players - games between adults who know the strategy are genuinely competitive.

2 to 5 minutes typical. Careful thinking players: 10 to 15 minutes. Maximum-length game (board fills completely): 42 moves. Connect Four is fast enough for multiple games in a single sitting.

Press keys 1 through 7 to drop a piece in that column (1 = leftmost, 7 = rightmost). Press R to reset the game. These shortcuts work in all game modes.

Yes. The Undo button takes back the last move. In vs AI mode, it undoes both your last move and the AI's response. You can undo back to the start of the game.