Play free online Sudoku with six difficulty levels — Easy to Extreme. No login, no download. Pick your difficulty and start solving.

What is Sudoku?

Sudoku is a logic-based number puzzle played on a 9×9 grid divided into nine 3×3 boxes. The goal is simple: fill every row, column, and box with the digits 1 through 9, with no digit repeating in any row, column, or box. Despite relying purely on logic — no maths required — Sudoku offers a satisfying challenge at every skill level.

How to play

Choose a difficulty — start with Easy to learn the patterns, then progress to Expert or Extreme for a real challenge.
Select a cell and tap a number on the pad to fill it in.
Use Notes to pencil in candidate digits when a cell has more than one possibility.
Use Hint (up to 3 per game) if you get stuck — it reveals one correct digit.
Avoid 3 mistakes — the game ends if you place three wrong numbers.

Every puzzle has exactly one solution, reachable by logic alone. Read our Sudoku strategy guide to learn techniques like naked singles, hidden pairs, and X-wings.