About Sudoku
Sudoku is a hugely popular number puzzle, and it needs no maths at all, just careful thinking and good eyes. The board is split into rows, columns and little boxes, and the goal is for every number to appear only once in each row, each column and each box.
This version takes you from easy to hard, whether you're just learning or love a challenge. There are 3 sizes: a small 4x4 board with the numbers 1 to 4 so you get the idea fast (it's also a great start for kids), a medium 6x6, and a big 9x9 just like regular sudoku but with lots of numbers filled in to keep it friendly. A brand-new puzzle is made every time, and each one has exactly one answer.
To keep things clear, the game highlights the row, column and box of the square you're on, lights up every copy of the number you picked, and shows a repeated number in soft red so you can check it calmly. Sudoku builds focus, logical thinking and patience at any age.
How to play
- Choose a board size: small, medium or big.
- Click or tap an empty square to select it.
- Type a number on the keyboard or use the buttons under the board.
- Make sure the number isn't already in the same row, column or box.
- If you make a mistake, erase it with the ⌫ button, and keep going until the whole board is filled in correctly.
Controls
| Keyboard | Arrow keys to move between squares, number keys to write, and Backspace or Delete to erase. |
|---|---|
| Mouse | Click an empty square, then pick a number from the buttons under the board. The ⌫ button erases. |
| Touch | Tap a square and choose a number from the big buttons under the board. |
Tips to win
- Look for a row, column or box that's missing just one number, and start there.
- Pick a number and see where it already appears: the highlighted squares show where it is, so you can spot where it's missing.
- If a number turns red it's repeated: change it instead of building on it.
- Start with the small board until you feel confident, then try medium and big.
Sudoku: questions and answers
What are the rules of sudoku?
Every row, every column and every small box must contain each number exactly once, with no repeats. On the 4x4 board the numbers go from 1 to 4, and on 9x9 from 1 to 9.
What age is sudoku good for?
From about age 6 on the small 4x4 board, and adults love it too: the medium and big boards give a bigger challenge. You don't need to add or subtract, only think.
Does every sudoku puzzle have an answer?
Yes, every puzzle is made by the computer and checked to have exactly one answer, so you can reach it by logic without guessing.
Can I play sudoku on a phone?
Yes, tap a square and choose a number from the big buttons under the board. It works on any phone, tablet or computer.