What if a Killer Sudoku puzzle seems unsolvable?

Good news first: every Killer Sudoku puzzle is tested before it reaches the game and has one valid solution. 🧩

If a puzzle looks impossible, it's usually because a number was placed in the wrong cell earlier or the numbers in a cage don't add up to the required sum. Both can be easy to miss.

💡 Two things that usually help

• Use a hint on a cell you're unsure about. You can also use hints on cells you've already filled to check if your answer is correct.
• Turn on Auto-Check for Mistakes in Settings to see incorrect numbers as soon as you enter them.

📩 Still stuck?

Send us a screenshot of the puzzle through the Help section. We'll take a closer look.