Sudoku Online: how to play

Free daily sudoku that starts gentle and gets tougher. Every grid has exactly one answer and can be solved by logic, so you never need to guess. Bruno says it's easy. Prove Bruno wrong.

How to play

• Fill every row, column and box with each number once.
• Tap a square, then a number on the pad. Keys 1–9 and the arrows work too.
• Switch to NOTES (or hold Shift) to pencil in possible numbers.
• A wrong number costs one of three hearts and doesn't stay on the grid.
• Placing a number removes it from your notes in the same row, column and box.

The five levels

1. Neon City: 4×4 warm-up
2. Rooftops: 6×6 with 3×2 boxes
3. Sewer: 9×9 easy
4. Robot Factory: 9×9 with fewer clues
5. Glitch Zone: 9×9 hard: the toughest grids need notes

Clear the Glitch Zone and the zones loop again as hard 9×9 grids, down to 24 numbers given. You have three hearts for the whole run, and the game is the same for everyone each day, so you can compare scores. Press M to turn the sound off or on.

Tips

• Look for the only square in a row, column or box where a number can go.
• When two squares in a box can only hold the same two numbers, those numbers are ruled out elsewhere in that box.
• Solve fast for a speed bonus.

Questions

Is this sudoku free?

Yes. Play free online on any phone, tablet or computer.

Does every sudoku have one solution?

Yes. Each grid is built so logic alone reaches the single answer.

Can I make notes?

Yes. Switch to NOTES or hold Shift while typing a number.

What happens when I make a mistake?

A wrong number costs one of your three hearts and isn't kept on the grid, so you can think again.