Killer Sudoku - Daily Challenge

Killer Sudoku is an advanced variant of classic Sudoku that combines standard Sudoku rules with cage sum calculations. Each dashed-line cage has a target number, and the digits inside must add up to that target.

At SimFuns, we publish a brand new Killer Sudoku puzzle every day at UTC midnight. Players worldwide tackle the same puzzle and compete for the fastest solve time on the leaderboard.

Whether you are a Sudoku beginner or a seasoned solver, the daily challenge is a perfect way to sharpen your logic and improve your speed. No sign-up required, just play.

How to Play Killer Sudoku

• Follow classic Sudoku rules: each row, column, and 3x3 box must contain digits 1-9 without repetition.
• Observe the cages: digits inside each dashed cage must sum to the target number shown in the corner.
• No digit may repeat within a single cage, even if they are in different rows, columns, or boxes.
• Combine Sudoku constraints with cage arithmetic to deduce the unique solution.

Solving Tips

• Start with small cages: fewer cells mean fewer possible combinations, making them easier to solve.
• Use the notes feature to mark candidate digits and avoid recalculating.
• Apply the Rule of 45: each row, column, and box sums to 45. Use this to eliminate impossible combinations.
• Practice daily to build intuition for common cage combinations (e.g., 3=1+2, 24=7+8+9).

Frequently Asked Questions