Sudoku
Fill the 9×9 grid with the digits 1-9. Every row, every column and every 3×3 box must hold each digit exactly once. Each puzzle has a single solution.
Sudoku
Tap a cell, then press a number key or 1-9 on the keyboard. Pencil mode writes candidates as small notes; Erase clears a cell.
Leaderboard
Top scores
How to play
- Tap an empty cell to select it; its row, column and box are highlighted.
- Pick a digit from the number pad or press 1-9 on the keyboard.
- Turn on pencil mode to note several candidates in a single cell.
- The puzzle is solved when every row, column and 3×3 box holds 1-9 once.
Frequently asked questions
Do the puzzles have a single solution?
Yes. Every puzzle is verified with a solver after it is generated, and only puzzles with exactly one solution are shown. So you can always progress by logic and never have to guess.
How are the difficulty levels decided?
Difficulty depends on how many digits are revealed at the start: Easy reveals more, Hard reveals fewer. The solution stays unique at every level.
What are pencil notes for?
When you do not yet know the definite digit for a cell, you can jot the possible candidates as small notes. Entering a definite digit clears the notes.