About the Sudoku
Classic 9×9 Sudoku with a puzzle of the day and unlimited new puzzles. Every puzzle has exactly one solution. Use pencil notes, undo and hints, and play with a mouse, touch or keyboard.
Key features
- A new puzzle of the day, the same for everyone
- Unlimited random puzzles
- Easy, medium, hard and expert levels
- Every puzzle has exactly one solution
- Pencil notes, undo, hints and mistake highlighting
- Mouse, touch and keyboard controls
How to solve Sudoku
Start with the easy wins, then move to notes:
- Scan for singles. Look at each digit in turn. If a box, row or column has only one cell where it can go, place it.
- Fill nearly complete areas. A row, column or box with one or two blanks is often easy to finish.
- Use notes. Pencil in every possible digit for the harder cells. A cell with only one candidate left is solved.
- Look for pairs. If two cells in a row can only be 4 or 7, no other cell in that row can be 4 or 7.
Keyboard controls
| Key | Action |
|---|---|
| Arrow keys | Move between cells |
| 1–9 | Place a digit (or a note in notes mode) |
| Backspace / Delete / 0 | Clear the cell |
| N | Turn notes on or off |
Sudoku facts
- There are about 6.67 × 10²¹ valid completed Sudoku grids.
- A Sudoku with a unique solution needs at least 17 given digits. This was proven by computer search in 2012.
- The modern puzzle was published in the US in 1979 as "Number Place" and named Sudoku in Japan, meaning roughly "single digits".
Related games
Sliding puzzle, mental math game, and number memory test.
How to use the Sudoku
- Choose a mode or difficulty, or keep the default.
- Press Start (or just click the board) and play with your mouse, finger or keyboard.
- Your score, time and moves are shown as you play.
- Your best score is saved in this browser, so you can try to beat it next time.