Sudoku Online
The classic number puzzle game. Fill the grid so each row, column, and 3x3 box contains digits 1-9.
How to Play Sudoku
Basic Rules
- Fill each row with numbers 1-9
- Fill each column with numbers 1-9
- Fill each 3x3 box with numbers 1-9
- No number can repeat in any row, column, or box
Tips for Beginners
- Start with rows/columns that have many numbers
- Use process of elimination
- Look for numbers that can only go in one place
- Use the hint feature when stuck
A worked example
A fixed teaching position, separate from your current game.
| 5 | 3 | 4 | 6 | 7 | 8 | 9 | 1 | · |
| 5 | 3 | 4 | 6 | 7 | 8 | 9 | 1 | 2 |
This row already contains 1, 3, 4, 5, 6, 7, 8 and 9. Only 2 is missing. Before entering 2 in a live puzzle, also check its column and 3×3 box. If either already contains 2, reconsider an earlier entry instead of forcing a row-only answer.