Free online Killer Sudoku with no ads and no sign-up. Easy to expert levels, a daily puzzle, every puzzle has exactly one solution, pencil notes, a cage sum helper, hints, undo, auto-save on phone and desktop, and leaderboards for puzzles solved and fastest hard solves. Killer sudoku adds cages to classic sudoku: the digits inside each outlined cage add up to the small number in its corner and never repeat, while rows, columns and 3×3 boxes still hold 1 to 9. Easy and medium reveal a few digits to get you started; hard and expert start with an empty grid, the way the classic is meant to be played.
How to play
Touch: tap a cell, then tap a digit on the pad. Notes toggles pencil marks, Erase clears a cell, Undo takes back a move, Hint fills the selected cell. Keyboard: arrow keys move, 1-9 enter a digit, Backspace or 0 erases, N toggles notes, H hint, U undo, Esc opens the menu.
New in v1.0
First release: Easy to Expert killer sudoku with a daily puzzle, cage sum helper, pencil notes, hints, undo, auto-save and leaderboards. Hard and Expert start with an empty grid; every puzzle has exactly one solution.
