MicroTools

Sudoku

Classic Sudoku with 3 difficulty levels, pencil notes, and mobile-friendly controls.

Sudoku

Fill the 9×9 grid so every row, column, and 3×3 box contains digits 1–9.

About Sudoku

Classic 9×9 Sudoku puzzle game optimized for mobile and desktop. Choose Easy, Medium, or Hard difficulty. Features tap-to-select, number pad, pencil mark notes, error highlighting, undo, and a timer. Generated fresh every game — no two puzzles are the same.

How to Use

  1. 1Choose a difficulty: Easy, Medium, or Hard.
  2. 2Tap any cell to select it (highlighted in blue).
  3. 3Tap a number on the number pad to fill the cell.
  4. 4Toggle Notes mode to write pencil marks in a cell.
  5. 5Tap Erase to clear a cell.
  6. 6Gray cells are given clues and cannot be changed.

Frequently Asked Questions

How do I play Sudoku?
Fill the 9×9 grid so every row, every column, and every 3×3 box contains the digits 1–9 exactly once. Tap a cell to select it, then tap a number on the number pad to fill it in.
What are pencil marks / notes?
Toggle Notes mode ON to write small candidate numbers in a cell without committing to them. This is useful for tracking possibilities in harder puzzles.
How is difficulty determined?
Easy has 36 given clues (more pre-filled numbers), Medium has 28, and Hard has 22. Fewer clues means more deduction required.
What happens when I make a mistake?
Wrong numbers are highlighted in red and counted in the Mistakes counter. The game does not end on mistakes — keep playing and correct them with the Erase button.
Are puzzles solvable?
Yes. Every puzzle is generated from a valid, fully-solved grid, so they all have at least one solution.

Tool Info

Category
gamer
Usage
Unlimited

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