Question 1

Is Killer Sudoku free?

Accepted Answer

Yes. Today's puzzles at all three levels are free every day, plus a few extra practice puzzles. While Suvi is new, every past puzzle is free to everyone too.

Question 2

How is killer sudoku different from sudoku?

Accepted Answer

No numbers are given at the start. The cages and their totals are the clues: work out which numbers can make each total, then use the usual sudoku rules for rows, columns and boxes.

Question 3

Does every puzzle have one solution?

Accepted Answer

Always. Each grid is checked by our solver before you see it, and it can finish every one with logic alone, so you never have to guess.

Question 4

What is the rule of 45?

Accepted Answer

The numbers 1 to 9 add up to 45, so every row, column and box does too. Add up the cages wholly inside one, and the squares left over must make up the difference, which often gives you a number outright.

Question 5

Is it the same puzzle for everyone?

Accepted Answer

Yes. Each day's puzzle at each level is the same for every player and changes at midnight in your own time zone, so you can race a friend on it.

Question 6

Can I play on my phone?

Accepted Answer

Suvi is built for phones first: the grid fits a portrait screen with big tap targets, and the cage totals stay readable. It works just as well on a tablet or a computer.

Killer Sudoku: Tuesday, 20 October 2026

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