About Sudoku
Sudoku is the world's most popular logic puzzle. Fill the 9×9 grid so every row, every column and every 3×3 box contains the digits 1-9 exactly once. Our generator builds a fresh, guaranteed-solvable puzzle every game.
How to Play Sudoku
- 1Tap a cell to select it, then type 1-9 or use the on-screen number pad.
- 2Pre-filled cells are fixed and cannot be changed.
- 3Conflicting digits are highlighted so you can spot errors immediately.
- 4Complete the whole grid correctly to win — fewer mistakes is a better score.
Tips & Strategy
- ◆Start with "scanning": pick a number and check which rows and boxes already contain it.
- ◆Look for cells with only one possible candidate before guessing anything.
- ◆Work box-by-box rather than row-by-row when the puzzle is fresh.
- ◆If you are stuck, hunt for pairs — two cells in a unit sharing the same two candidates eliminate those digits elsewhere.
Frequently Asked Questions
Does every puzzle have exactly one solution?
Our generator creates the puzzle by removing digits from a valid completed grid, so a correct solution always exists.
Is guessing ever necessary?
At this difficulty, no — every puzzle can be completed with scanning and single-candidate logic, no bifurcation required.
Why is my score counted in mistakes?
Sudoku rewards precision, so the best score is the fewest wrong entries — zero-mistake solves are the goal.