The rules in one minute
Fill every empty cell with a digit from 1 to 9 so that each row, each column and each 3×3 box contains every digit exactly once. That’s all. You never need maths; sudoku is about logic.
Your first technique: scanning
Pick a digit, say 1. For each 3×3 box that doesn’t have a 1 yet, look at the rows and columns crossing it. If a 1 already sits in a row or column, the box can’t take a 1 there. Often only one cell is left, and that’s where the 1 goes. Repeat for every digit and you can solve most easy puzzles.
Beginner tips
- Keep Show mistakes on while you learn: a wrong digit turns red right away.
- Click a filled number to highlight all the same digits; it makes scanning much easier.
- Use Hint when you’re stuck and look at why that number fits.
- Ready for more? Move up to Medium, try the daily sudoku, or read our sudoku techniques guide.