Sudoku

Try it right away, without an account: 4 rounds a day. With an account you play as much as you like and get on the top list. Free during the beta, no ads and nothing to download. Play in the browser on a computer, tablet or phone.

How to play

Fill in the digits 1–9 so that every row holds all nine digits once.
Every column also holds all nine digits once.
And so does every 3 × 3 box, inside the thick lines.

Using the game

Pick an empty cell by clicking or tapping it. Drag across several cells to mark them all at once.
Enter a digit with the buttons or the keyboard.
Turn on Notes to write small candidate digits in the cell, like pencil marks in the newspaper.
Mistakes are marked in red (can be turned off in Settings).

Difficulty

Easy: Many digits from the start. Every step is a "single": only one digit fits the cell, or the digit fits only one place in its row, column or box. 5–10 minutes.
Medium: Fewer digits. You need to cross out candidates, for example when a digit in a box can only go in one row. 10–20 minutes.
Hard: Few digits. Needs pairs and triples and long chains of steps. 20–40 minutes.
Expert: Needs advanced patterns such as X-wing, swordfish and XY-wing. For a real challenge.

Keyboard

Arrow keys: move between cells
Click and drag: mark several cells (diagonally too)
Ctrl/Shift + click, Shift + arrow: add cells to the marking
A: mark all empty cells
Esc: clear the marking
Z: digits
X: notes
N or space: switch between digits and notes
1–9: write in every marked cell
Shift + 1–9: write in the other mode (note instead of digit and the other way round)
Backspace / Delete / 0: erase the marked cells
Ctrl + Z or U: undo
H: hint
P: pause

Questions

Is there always a unique solution?
Yes. Every puzzle is made here and checked so that it can be solved by logic all the way, without guessing. That means there is only one solution.

Where does sudoku come from?
The puzzle was made in the USA in the 1970s as Number Place, and got its name and became popular in Japan. Around 2005 it spread all over the world.

Is my puzzle saved?
Yes, in this browser. You can close the page and continue later. Best times are saved per difficulty.

Can I play the same puzzle as a friend?
Yes. Tap the puzzle code and send the link.

Questions and answers

How do you play Sudoku?

The classic number puzzle: fill in 1 to 9 so that every row, column and box holds each digit once. A new puzzle whenever you like, from easy to expert. The full rules are above.

How many can play Sudoku?

Sudoku is played alone.

How long does a game of Sudoku take?

About 5–60 minutes.

Can you play Sudoku without an account?

Yes. You can try 4 rounds a day without an account. With an account you play as much as you like.

Can you play Sudoku on a phone?

Yes. The game runs in the browser on phones, tablets and computers. There is nothing to download.

Does it cost anything to play Sudoku here?

No. Spelbordet is free during the beta and has no ads.