How to Play Killer Sudoku

Killer Sudoku combines standard Sudoku rules with "cages" — groups of 2–5 cells outlined in color. The small number in each cage's corner is the sum of all digits in that cage. No digit may repeat within a cage.

Standard Sudoku rules Digits 1–9 appear once in each row, column, and 3×3 box.

Cage sums The digits in each cage must add up to the clue shown.

No cage repeats A digit cannot appear more than once within a single cage.

No given digits The grid starts completely empty — cages are your only clues.

Killer Sudoku Strategy

Start with forced cages

A 2-cell cage summing to 3 can only be {1,2}. A 2-cell cage summing to 17 can only be {8,9}. Find all such forced cages before doing anything else.

Use the 45 rule

Every row, column, and box sums to exactly 45. If you know all cage portions in a row except one cell, subtract from 45 to find the missing digit.

Frequently Asked Questions

Is Killer Sudoku harder than regular Sudoku? +

It depends on difficulty. Easy Killer Sudoku can be easier than Hard regular Sudoku because forced cage combinations provide a lot of information. Hard Killer Sudoku is generally harder than Hard regular Sudoku.

Do I need to know regular Sudoku to play? +

It helps but is not required. The standard Sudoku row/column/box rules still apply and are necessary for solving, but cage sum logic provides additional constraints that can unlock cells independently.

Is Burmly Killer Sudoku free? +

Completely free. No account, no ads, unlimited puzzles.

Play Killer Sudoku Online Free

How to Play Killer Sudoku

Killer Sudoku Strategy

Frequently Asked Questions