How to play Sudoku
Play free Sudoku online from Easy to Expert. Every puzzle has one solution, with notes, hints, undo and saved progress. No sign-up needed.
- Controls
- Select a cell, then use the number pad or type 1–9. Arrow keys move the selection. Backspace or Delete clears an entry; N toggles Notes.
- Features
- Four difficulty levels, one solution per puzzle, pencil notes, hints, undo and saved progress.
- Processing
- Games and saves stay in your browser; optional visit analytics are described in our privacy policy
- Choose Easy, Medium, Hard or Expert. A puzzle is ready when the page opens; New puzzle creates another at the selected level.
- Fill each row, column and 3 × 3 box with the numbers 1–9, without repeating a number. The starting clues cannot be changed.
- Turn on Notes to record possible numbers in an empty cell. Select a candidate again to remove it. Entering a number also clears matching candidates from its row, column and box.
- Use Undo to step back or Hint to reveal a correct number. Complete the grid to finish and record your time.
FAQ
Does each puzzle have exactly one solution?
Yes. The generator checks for a unique solution while creating each puzzle.
Which difficulty should I choose?
Start with Easy to practice the rules. Medium gives you fewer starting clues; Hard and Expert leave more to work out. Changing difficulty starts a new puzzle.
Does a red number mean it is definitely the wrong answer?
Red marks a duplicate in the same row, column or box. An entry can still be wrong without creating a duplicate, so the absence of red is not proof that it is correct.
What does Hint reveal?
It fills the selected cell with the correct number if that cell needs it. Otherwise it finds another empty or incorrect editable cell. It counts the hints used, but does not explain a solving technique.
Can I use a keyboard or phone?
Yes. On a computer, select the board and use 1–9 and the arrow keys. On a phone, tap a cell and use the number pad below it. Notes, Erase, Undo and Hint work on both.
Will my puzzle still be here later?
Your current game is saved in this browser. Return on the same device and browser to continue. Clearing site data removes the save; progress does not sync between devices.