Daily Killer Sudoku

Killer Sudoku follows the normal sudoku rules, with each row, column and 3x3 box holding 1 to 9 once. On top of that the grid is divided into cages, each with a small number in its corner. The digits in a cage must add up to that number and may not repeat within the cage. Often the grid starts with no digits at all, so every number has to be worked out from the sums.

On puzzle-killer-sudoku.com the daily game is the Special Daily Killer Sudoku. Every player gets the same grid on a given date, and the date sits under the board. The 2 October 2026 puzzle was a full 9x9 grid with no digits given. Some days add a twist of their own: the 28 October daily was a Killer Sudoku X, where both main diagonals must also hold 1 to 9, and a note above the grid said so. The standard sizes are listed by box size, 2x2, 2x3 and 3x3, each in Easy, Normal and Hard, and there are weekly and monthly specials and a Hall of Fame for the standard sizes. The site is free with ads, a banner above the board and a rail beside it. Patrons, from $1 a month, can hide them, and it links to the PuzzleGym app for iPhone and Android. Patrons of the site can go back through the last 30 daily puzzles; everyone else plays the current day's.

Killer Sudoku suits sudoku players who want more arithmetic, and Kakuro players who want the structure of rows, columns and boxes to lean on.

The site comes in twelve languages, from German and Polish to Japanese and Vietnamese, each on its own subdomain with the same daily grid.