Free Printable Medium Killer Sudoku
A freshly generated medium killer sudoku — the classic challenge most papers publish.
Killer SudokuFree printable medium killer sudoku puzzles — the difficulty most newspapers publish under their daily killer slot. Killer uses classic 9×9 rules (one of each digit per row, column, and 3×3 box) plus a cage layer: dashed-outlined regions, each with a target sum and a unique-digits constraint. The puzzle ships empty; cages and sums are the entire opening position.
Medium killer mixes two- and three-cell cages with a handful of four-cell groups. The cage-combination work is now meaningful: you'll recognise that a 3-cell cage summing to 6 must be 1-2-3, a 2-cell cage summing to 5 must be 1+4 or 2+3, and so on. You'll also start applying the 45 rule — every row, column, and 3×3 box sums to 45, so the cage sums crossing a row plus or minus any partial cells must reconcile to 45. That single trick unlocks most medium puzzles.
Expect twenty-five to forty-five minutes for a clean solve. Print one full-page sheet, brew a coffee, and settle in. Free, no account, no watermark, freshly generated every load.
Frequently asked questions
Quick answers about printing sudoku from Sudoku247Online.
- What is killer sudoku and how does it differ from classic?
- Killer sudoku uses the same 9×9 grid as classic, but the puzzle ships empty. Cells are grouped into outlined regions called cages, and each cage carries a target sum. Standard row/column/box rules still apply, plus digits inside a cage must be unique and add up to the cage's sum.
- Why is the printed grid completely empty?
- Killer puzzles have no starting digits — the cages and sums are the puzzle. Everything you need to solve is right there: the cage outlines and the small sum number in the corner of each cage's anchor cell.
- What do the small numbers in the cells mean?
- Each small number in the top-left corner of a cell is the sum target for the cage that cell anchors. Cage boundaries are drawn as dashed lines. Every cell belongs to exactly one cage.
- How long does a killer sudoku take to solve?
- Easy killer takes 15–25 minutes, medium 25–40, hard 40–70, expert often over an hour. Cage-sum combinations open up most of the early moves; classic sudoku scanning closes them.
- What techniques are essential for killer sudoku?
- Cage-sum arithmetic is the killer-specific layer: the '45 rule' (every row/column/box sums to 45), cage combinations (e.g. a 3-cell cage summing to 6 must be 1-2-3), and innies/outies. Standard sudoku techniques (naked singles, hidden singles, pointing pairs) carry over for the placement step.
- Are the solutions printed with the puzzle?
- Not on the standalone killer printables yet — solving online at /killer-sudoku reveals the solution on completion. A 'Print with solutions' option for killer is on the roadmap.