About Sudoku
Sudoku is the world's favorite number-logic puzzle: fill the 9×9 grid so every row, column and 3×3 box contains the digits 1 through 9 exactly once. No math needed — just pure deduction.
How to play Sudoku
Pick a difficulty and press New Game, then tap a cell and enter a digit 1–9. Every number must be the only one of its kind in its row, column and box — the givens make each puzzle solvable by logic alone.
Questions & answers
- How do you play Sudoku?
- Fill every empty cell with a digit 1–9 so no row, column or 3×3 box repeats a number. Start where a row or box is nearly full — those cells often have only one possible answer.
- Is Sudoku math?
- No arithmetic at all — the digits are just symbols. It's pure logic and elimination, which is exactly why it's such good thinking practice for kids from about age 8.
- Is Sudoku free here?
- Yes — free unlimited puzzles in three difficulties, with a timer and checking, right in the browser on crumble.lol.