1. Learn the Goal
A valid solution has no repeated number in any row, any column, or any 3x3 sub-grid.
How to Play Classic Sudoku
Fill every row, column, and 3x3 box with numbers 1 to 9 exactly once.
2. Start With Singles
Look for cells where only one number can fit based on nearby filled numbers.
3. Use Notes
Add candidate notes when unsure. Reduce them as the board becomes clearer.
4. Scan Every Unit
Re-check each row, column, and box to find hidden singles and remove impossible candidates.
5. Use App Tools
Use Puzzle Scan to import boards quickly, and AI Analysis when you want guided help without revealing the full answer.
6. Finish Cleanly
Before completion, verify there are no duplicates and no leftover notes.
Quick Tips
Prioritize accuracy over speed first. As patterns become familiar, your solve time improves naturally.