Sudoku

Fill the grid so every row, column and box contains each number exactly once. Choose a 4×4, 6×6 or classic 9×9 grid.

Difficulty
High score
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Select an empty square, then a number. Each row, column and box holds every number once. Easy is 4×4, Standard 6×6 and Hard the classic 9×9. Repeats are shown in red. A hint fills one square but costs points.

How to play
  1. Select a square, then choose a number.
  2. Every row, column and box holds each number exactly once.
  3. Fill the whole grid. Hints help but cost points.
Tips and tricks

A few ideas that make Sudoku easier and more fun:

  • Look for a number that appears often and see where it can still go.
  • Rows, columns or boxes that are almost full have only one answer left.
  • Selecting a square highlights its row, column and box. Use it to rule numbers out.
About Sudoku

Play Sudoku online

Sudoku is a number-placement puzzle loved in newspapers and apps around the world. Every puzzle here has exactly one solution, and there is no timer.

Why it works

You eliminate possibilities, hold several constraints in mind and check your reasoning. The task uses logic, attention and patience.

These are the skills used during play; improvement outside the game is not established.