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Killer Sudoku Generator
Sudoku with sum cages instead of given digits — every printable puzzle is verified to have exactly one solution and comes with its answer key.
Prefer classic clues? Try the Sudoku Generator →About Killer Sudoku
Killer sudoku looks like an empty sudoku grid crossed with jigsaw pieces: the grid is partitioned into cages, each printed with a sum, and no digits are given at all. Digits 1-9 may not repeat within a cage, so cage sums plus standard sudoku rules are enough to reconstruct everything — provided the puzzle has exactly one solution, which this generator verifies with an exhaustive solver before publishing anything.
Tips
- Cages of two cells with small sums (3, 4, 16, 17) have very few digit splits — start there.
- Remember cage sums include the 45 rule: every row, column, and box totals exactly 45.
- Digits never repeat inside a cage, which is often stronger than the box constraint.
FAQ
- Does every puzzle have a unique solution?
- Yes. Each generated grid is checked by a solver that counts solutions up to two; only puzzles with exactly one solution are published. This check runs even though it takes a few extra seconds.
- How is this different from regular sudoku?
- No starting digits are given. Instead, cages with printed sums provide all the information, and their shapes constrain where repeats are forbidden.
Make the worksheet useful
Choose, check, then download
Sudoku solvers ready to work from cage sums instead of given digits.
Suggested workflow
- 1Pick a difficulty and how many puzzles to include.
- 2Check the preview — cages show their sums with bold walls.
- 3Download puzzle pages followed by the solved answer grids.
Why this format
Every generated grid passes a two-solution-count check, so printed puzzles are always uniquely solvable.
Sample PDF
Set difficulty to easy for cages that resolve quickly with pairs and the 45 rule.