Sudoku
Warming up Sudoku…
Screenshots
How it's going
Counting…
Achievements
How to play Sudoku
Sudoku is a number puzzle. You fill the empty squares so that every row, every column and every box has each number exactly once. You do not need to be good at maths, only at spotting what is missing.
Step by step
- Pick a size. 4×4 uses the numbers 1 to 4, 6×6 uses 1 to 6, and 9×9 uses 1 to 9.
- The printed numbers stay where they are. You fill in the empty squares.
- Tap a square, then tap a number to write it there.
- A number can appear only once in each row, each column and each box. Two of the same turn red.
- Fill every square correctly and the puzzle is solved.
Tips
- Look for a row, column or box that is almost full. The missing number is easy to find.
- Pick one number and look for every place it could go.
- Turn on Notes to pencil in small numbers when you are not sure yet.
- Tap a number with no square chosen to see everywhere it already is.
- Stuck? A hint writes in a number that has to go there, and tells you why.
Questions
Is Sudoku good for kids?
Yes. Start with 4×4, which is small and quick. When it feels easy, move to 6×6 and then 9×9.
Do I ever have to guess?
No. Every puzzle here can be solved by thinking it through.
Is there a time limit or lives?
No. There are no lives and no time limit.
What is today's puzzle?
Every day there is a new puzzle that is the same for everybody. Its size changes from day to day.
About this game
Number puzzles on a chalkboard. Fill the grid so every row, column and box has one of each number. Start small with 4 × 4 and work up to the big grid.
Your host
Hatchling 4 of 12
Chalky
Keeps the chalkboard in Sudoku.
- Colour
- White
- Personality
- Curious
- Ability
- Water Breathing
- Height
- 0.62 m
Our research shows a Chalky master speeds up cloning. The numbers are secret, of course.
What changed
v1.0.0The Chalky cheers each time you finish a box.
On a tall phone, the 4×4 and 6×6 number keys sit in two rows of wider keys.
The game is drawn at your screen's own sharpness, so nothing looks blurred.
A Chalky joins the game: beside the board, in the hall and when you win.
New schoolroom sounds, words and chalk boxes.
Sudoku has its own schoolroom: a chalk slate in a wooden frame.