How to play Sudoku
- Tap an empty square to select it: its row, column and box light up.
- Tap a number on the keypad, or type it on your keyboard.
- Each number appears exactly once in every row, every column and every box.
- A wrong number turns red and counts as a mistake; a right one turns green and stays.
- Fill every empty square to solve the grid.
Tips
- Start with the numbers that already appear most often in the grid.
- Switch on Notes (or press N) to pencil in the numbers a square could still take. They clear themselves as you place numbers.
- Stuck? Hint (or H) fills in the easiest square left. It costs a few points, and the diamond badge is only for grids solved without one.
- Undo (or Ctrl+Z) takes back your last move, notes included.
- The small figure under each key tells you how many of that number are still missing.
About Sudoku
Sudoku is a logic puzzle played with numbers but without any arithmetic: you only need to reason about where each number can go. It became a worldwide favorite in the 2000s and remains one of the best daily brain workouts.
Every grid here is generated on the spot and checked to have exactly one solution. Five levels take you from a tiny 4 x 4 grid with many clues to the classic 9 x 9 with very few, so you can start gently and climb at your own pace.
Points and badges
Finishing a game of Sudoku earns points for your level. Four badges are waiting in this game, from bronze to diamond: each one says what to do and adds bonus points.
Questions
Do I need to be good at math to play Sudoku?
No. Sudoku uses numbers as symbols: it is pure logic, with no calculation at all.
Does every grid have a single solution?
Yes. Each grid is checked when it is created so that exactly one solution exists.
Which level should I start with?
Try Starter or Easy (4 x 4) to learn the rules, then Medium (6 x 6). Hard and Expert are full 9 x 9 grids.
How do I earn more points?
Harder grids give more points, and a grid solved without any mistake earns a bonus.