Fresh puzzles everyday
sudoku.day publishes classic and killer puzzles daily across four difficulty bands, from easy to expert. Play in the browser with pencil marks, colors, and a digit lens, or print a clean sheet. No account needed! Sign in only if you want your solves and streaks to follow you across devices.
What is killer sudoku?
Killer sudoku starts with a completely empty grid. Instead of given digits, the grid is carved into outlined groups of cells called cages, and each cage shows the total its digits must add up to. Those sums are the only clues; everything else is deduction. A two-cell cage totalling 3 can only be 1 and 2 — and because every row, column, and box adds to 45, the arithmetic reaches further than the cages alone suggest.
Logic only, never guessing
Every puzzle has exactly one solution, reachable without guessing, and is graded by the techniques needed to finish it. The hint button reveals the next move one step at a time, and the technique guide explains each move on a real board.