How to play Sudoku
Sudoku is a logic puzzle played on a 9×9 grid divided into nine 3×3 boxes. The goal is simple: fill every row, every column and every box with the digits 1 to 9 – without repeating a digit. Despite the numbers, no math is needed; sudoku is purely about logic and deduction.
About Sudoku
Start with the easy level and look for rows, columns or boxes that are almost complete. Use notes to keep track of possible candidates in each cell. When you are stuck, the smart hint shows you the next logical step and explains the technique – so you improve with every puzzle.
Why Sudoku Luna?
- Four difficulty levels from easy to expert
- Daily challenge with a global leaderboard
- Smart hints that teach real solving techniques
- Notes, undo/redo and automatic error checking
- Dark and light mode with an elegant design
- Print puzzles as PDF in multiple layouts
Frequently asked questions
Is Sudoku Luna really free?
Yes. All puzzles, the daily challenge, statistics and the print function are completely free to use.
Do I need an account to play?
No. You can play instantly. An account is only needed if you want to appear on the global leaderboard and sync statistics across devices.
How is the score calculated?
The score is based on difficulty, solving time, mistakes and hints used. Daily challenge streaks add a bonus of up to 50%.
Can I print puzzles?
Yes. The print page generates fresh puzzles as a PDF with 1, 2, 4 or 6 grids per page, optionally with solutions.