QuietdokuHard Killer Sudoku
Hard puzzles ask for the rule of 45 across two or three rows, and the difference between an innie and an outie. Expect to keep pencil marks.
Loading puzzle…
More killer sudoku
Easy Killer Sudoku
Cage combinations only. The best way to learn.
Play →Medium Killer Sudoku
Adds the rule of 45 and cages locked inside a box.
Play →Expert Killer Sudoku
The hard techniques with bigger cages.
Play →Extreme Killer Sudoku
Combination exclusion and X-Wing style patterns. Still no guessing.
Play →Daily killer sudoku
One new puzzle per level every day, the same for everyone.
Play →Rules and combination chart
Every cage combination on one page, plus the three tricks that solve most puzzles.
→Quietdoku for iPhone and Android
Take the quiet with you.
The app works offline and adds the parts that make a habit stick.
- Four daily puzzles, one per level
- Streaks and collectible achievement cards
- Worldwide and country rankings, seasons
- Challenge a friend with a link
- Sign in with Apple or Google to keep progress across phones
Scan to download
Free · No ads · Optional Pro for unlimited practice