How to play Sudoku
The grid is made of nine rows, nine columns, and nine 3×3 boxes. Your job is to fill every empty cell with a digit from 1 to 9 so that no digit repeats in any row, any column, or any 3×3 box. The puzzle starts with some numbers already placed — those are your clues. Click a cell and type a number (or use the number pad); press 0 or Delete to clear a cell. Any digit that breaks a rule turns red. Solve the whole grid to win.
Tips & strategy
- Start with the fullest areas. Rows, columns, or boxes that already have many numbers are the easiest to complete.
- Hunt for "singles." If a cell can only be one possible digit, fill it in — those chains unlock the rest.
- Scan for each digit. Pick a number, say 7, and see which boxes still need it and where it can legally go.
- Use pencil logic, not guesses. A real Sudoku always has a logical next step — guessing usually leads to mistakes.
About the game
Sudoku's number-placement puzzles took the world by storm in the mid-2000s, appearing in newspapers everywhere despite containing no arithmetic at all — it's pure logic. Its enduring popularity comes from the clean, satisfying "aha" of each deduction and the fact that every puzzle, no matter how fiendish, can be solved by reason alone.