Killer Sudoku Online

About Killer Sudoku Online

Killer Sudoku Online has been posting puzzles for many years; the daily killer had reached number 7,592 by October 2026. Its front page carries five puzzles: the daily killer sudoku, a weekly killer, a daily and a weekly Greater Than sudoku, and a weekly Greater Than killer.

In a killer sudoku the usual rules apply, with 1 to 9 once in every row, column and 3x3 box, but the grid is divided into dotted cages whose cells must add up to the small number shown, with no repeats inside a cage. A Greater Than sudoku instead shows inequality signs between neighbouring cells. The daily puzzles get harder as the week goes on, with Sunday usually hardest, and the weekly ones are tougher still.

The online player lets you enter several candidate values in a cell, mark guesses and sure values, undo, check, ask for a hint and save your progress, and its sum calculator lists the ways to make a cage total. Every puzzle can also be downloaded as a PDF. Solutions to the dailies appear in the archives the next day, where older puzzles are also sorted by difficulty.

It suits sudoku players who enjoy arithmetic and like a classic, no-frills site with printable puzzles.

How to play Killer Sudoku Online

1. Open the site and choose the daily killer sudoku, then Play On-line or download the PDF.
2. Fill the grid so every row, column and 3x3 box holds 1 to 9 once.
3. Make the numbers in each dotted cage add up to its total, with no repeats in a cage.
4. Use the sum calculator for the possible combinations of a cage.
5. Check your grid, and look up the solution in the archives the next day.

Tips

• Learn the fixed combinations, such as 3 in two cells being 1 and 2.
• Use the 45 rule: each row, column and box sums to 45.
• Start the week on the easier puzzles and build up to Sunday.
• Mark uncertain entries as guesses so you can undo them later.

Questions