Pick a square, then a number (or type it). The arrow keys move the selection.
How to play sudoku
The grid is made of rows, columns and boxes (the squares with a thick border). The goal: put a number in every empty square so that each number appears only once in every row, every column and every box.
To start, choose the 4 × 4 grid (numbers 1 to 4), then move on to 6 × 6 and 9 × 9. Tip: first look for a row or box that is almost full.
Stuck? The “Hint” button fills the selected square, and “Show mistakes” turns wrong numbers red.
Frequently asked questions
Is sudoku suitable for children?
Yes: the 4 × 4 and 6 × 6 grids suit children from about 6, and the 9 × 9 grids older children and adults.
Is there only one solution?
Yes, every grid is drawn at random and checked to have exactly one solution.
Is my grid saved?
Yes: the current grid is kept on this device. You can close the page and carry on later.