Free Killer Sudoku Generator — Printable Puzzles with Cage Sums

What Is Killer Sudoku?

Killer sudoku combines classic sudoku rules — each row, column, and 3×3 box contains the digits 1–9 exactly once — with cage constraints: the grid is also divided into irregularly-shaped “cages,” each with a printed sum, and the digits inside a cage must add up to that sum without repeating any digit. Most puzzles start with few or no given digits, since the cage sums provide most of the deduction power.

How to Solve a Killer Sudoku

1. Start with small cages. A 2-cell cage summing to 3 can only be 1+2; a 3-cell cage summing to 6 can only be 1+2+3.
2. Use the “45 rule.” Every row, column, and box sums to 45, so you can often deduce a single cell by subtracting known cage sums from 45.
3. Cross-reference sudoku rules with cage sums to narrow candidates the same way you would in standard sudoku.
4. Fill in confirmed digits and repeat until the grid is complete.

Who Uses Our Killer Sudoku Generator?

Teachers use it for logic and arithmetic practice; Amazon KDP publishers use it to build activity books in a high-demand, under-served puzzle niche; and logic-puzzle fans use it for a tougher daily challenge than plain sudoku. Prefer to play on screen first? Try the interactive killer sudoku.

Frequently Asked Questions