Killer Sudoku
About Killer Sudoku
Killer Sudoku, also called Sumdoku, combines classic sudoku with math. You fill the grid so every row, column and box contains the numbers 1 to 9 exactly once. The grid is also split into colored cages, each showing a target sum in its corner that the numbers inside it must add up to.
How to play Killer Sudoku
Fill every cell with a number from 1 to 9. Each row, column and 3x3 box must contain every number only once, just like standard sudoku. On top of that, the grid is divided into cages marked by background color. The numbers in a cage must add up to the total shown in its top left corner, and no number can repeat within the same cage.
Tips for playing Killer Sudoku
- Start with cages that have very low or very high totals, since they allow fewer possible number combinations.
- A cage with only two cells often has just one or two possible number pairs that add up to its total, so check those first.
- Use the normal sudoku rules of rows, columns and boxes together with the cage sums to narrow down candidates faster.
Killer Sudoku screenshots
Frequently asked questions
What is Killer Sudoku?
Killer Sudoku, or Sumdoku, is a sudoku variant where the grid is divided into colored cages, each with a target sum that the numbers inside it must add up to, on top of the normal row, column and box rules.
Can numbers repeat inside a cage?
No. The same number cannot appear more than once within a single cage, in addition to never repeating in a row, column or box.
Do I need to download anything to play?
No, Killer Sudoku runs directly in your browser for free, with no download needed, and works on both phone and computer.
