Is Duo Sudoku free? Do I need an account?

It is free and there is no sign-up. You type a name when you arrive and start playing.

Duo Sudoku: sudoku you play against a friend

Q: How do you play sudoku with two players?

In Duo Sudoku both players fill in the same puzzle. Each correct number scores points, bonus squares score double or triple, and a wrong number costs a point. When the board is full or the clock runs out, the higher score wins.

Q: Can I play sudoku online against a friend?

Yes. Tap Play online, then Challenge a friend, and send them the link, or make a room and tell them the 5-letter code. They open it on their own phone or computer and you play the same puzzle live.

One puzzle, two players, bonus squares. Race a friend to fill in the same sudoku, side by side on one screen or online on two devices. The higher score wins.

Play Duo Sudoku free No sign-up · Works on phones · Games take 3 to 10 minutes

A Duo Sudoku game part way through: blue numbers from one player, black numbers from the other, and ×2 and ×3 bonus squares still to claim — Blue and black are the two players. The ×2 and ×3 squares are worth double and triple.

How to play sudoku with two players

The board is an ordinary sudoku: every row, column and 3×3 box must end up holding 1 to 9 once each. The difference is that you share it with someone else, and every number you place is a point for you and not for them.

Place a correct number and you score it. A 7 is worth 7 points.
Claim the bonus squares. Each puzzle has four ×3 squares and eight ×2 squares. A number placed there scores triple or double.
Don’t guess. A wrong number costs you 1 point and the square stays empty for anyone to take.
Win on points. When the board is full or the clock runs out, the higher score wins. A tie is possible.

Prefer a deeper game? Switch on scoring by difficulty. Numbers that still have the most copies left to place become the most valuable, so the scores shift as the board fills.

Two ways to play

Rapid fire

The default. No turns: both of you place numbers as fast as you can until the board is full or the game clock ends. Pick 3, 5 or 10 minutes.

Take turns

One number each, in turn, with 30 seconds per move. Add a 3 or 5 minute clock per player if you want the pressure of a chess clock.

Choose Medium for a quick, friendly race or Hard when you both know your sudoku.

Play multiplayer sudoku online

Your friend doesn’t need to be in the same room. Tap Play online, then Challenge a friend and send the link, or Make a room and tell them the 5-letter code. They open it on their own phone or computer, and every number either of you places shows up on both screens straight away.

Sitting together? Put one laptop or tablet between you and play on one screen. Blue and black numbers show who placed what.

Why it’s good for a break at work or school

A game takes 3 to 10 minutes, so it fits into a coffee break.
Nothing to install and no accounts: send a link and you’re playing.
It rewards the same skill as normal sudoku, so it’s fair whether you’re playing a colleague, a friend or family.

Questions

How do you play sudoku with two players?

You both fill in the same puzzle. Each correct number scores points, bonus squares score double or triple, and a wrong number costs a point. When the board is full or the clock runs out, the higher score wins.

Can I play sudoku online against a friend?

Yes. Tap Play online → Challenge a friend and send them the link, or make a room and tell them the 5-letter code. You play the same puzzle live on two devices.

Is it free? Do I need an account?

It’s free and there’s no sign-up. You type a name when you arrive and start playing.

How long does a game take?

Rapid fire games last 3, 5 or 10 minutes. 10 minutes is the default.

Does it work on a phone?

Yes. It runs in any modern browser on phones, tablets and computers.

Challenge someone now

Pick a name, send a link, and find out who’s faster.

Play Duo Sudoku