How to play Sudoku
Fill the nine-by-nine grid so that each row, each column and each three-by-three box contains the numbers 1 through 9 exactly once. Starting numbers stay fixed. Every new board is generated here and checked to have exactly one solution. Use pencil notes to keep track of possible numbers, and work through the grid at your own pace.
Choose your difficulty
| Level | What changes |
|---|---|
| Easy | More starting clues leave fewer blank cells. |
| Medium | Fewer starting clues give you more of the grid to work out. |
| Hard | The fewest starting clues in this collection. Labels describe clue density rather than a human-solving technique rating. |
Controls
Select a cell, then type 1–9 or use the number buttons. Arrow keys move. N toggles notes; Delete or Backspace clears an entry. Check marks incorrect entries, and Hint supplies one correct number.
A tip for your first round
Start with a row, column or box that already contains several numbers. Check every candidate against all three constraints before filling it in.
Play without installing anything
This version of Sudoku plays in a modern browser. Follow the controls above and use a keyboard or the on-screen buttons where available. No account or payment is required. Any supported scores or progress are kept on this device, rather than synced to an account.
Sudoku questions
Does each Sudoku have one solution?
Yes. The generator removes clues only while the puzzle retains exactly one solution.
Can I make pencil notes?
Yes. Turn Notes on and select candidate numbers for an empty cell. Turn it off to enter an answer.
Does my Sudoku progress save?
Your current puzzle, entries and notes save in this browser when local storage is available.
Read the Sudoku playing guide or browse more puzzle games.
