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Sudoku, free to play

Fill the grid so every row, column and box has each number once. Pick 4x4, 6x6 or 9x9, and take a new puzzle every day.

Full rules and tips: how to play Sudoku

  • 4x4, 6x6 and 9x9
  • A daily puzzle
  • Hints
  • Mistakes show as you go

How to play

  1. Pick a size and level

    Start small with 4x4 or 6x6 if you are new, or go straight to 9x9. There are three levels for each size.

  2. Fill the grid

    Tap a square, then a number. Each number goes once in every row, column and box. There is always a square where only one number fits.

  3. Stuck? Use a hint

    A wrong number turns red as soon as you place it. Press Hint to fill in one square, or the erase key to clear one.

Ways to play

Good to know

Quick answers about playing Sudoku on Wittlo.

Learn while you play

Sudoku is a good, light workout for careful number thinking. Fun first.

Is Sudoku on Wittlo free?

Yes. All of it is free to play, and you can start straight away with nothing to install.

Does every puzzle have just one answer?

Yes. Every puzzle is checked by a solver to have exactly one solution.

Do I need to guess?

Not on easy. Easy puzzles can be finished with simple logic (naked and hidden singles). Medium and hard leave fewer clues, so you may need to try an idea and see where it leads.

What if I make a mistake?

A wrong number turns red straight away, so you can fix it at once. You can turn that off with the Show mistakes as I go box.

Can I print a puzzle?

Yes. The printable sheets give you a page of puzzles with answers.

Will my game be saved?

Yes. If you leave a puzzle half finished, it picks up where you stopped next time you open it on the same device. Nothing is sent anywhere.

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