New game
Classic Sudoku structure plus Killer cages: outlined regions with a small sum clue—digits in each cage sum to that clue, with no repeats inside a cage. More in our basic rules guide. Select a cell, then use the number pad or keyboard. Turn on Notes to mark candidates; use Hint if you're stuck.
About Hard puzzles
For experienced solvers. Fewer givens mean you'll rely on notes, pairs, and triples. No guessing—pure logic. Use our Techniques guide to spot patterns.
How we generate puzzles: We build cages from the unique solution grid and retry until Killer rules admit a single filling—then you solve from an empty start. Cage count scales with difficulty. Read more.
Who it's for: ProPuz is free, with no sign-up, for all ages. Whether you're a beginner or an expert, you can play on any device. About us · Techniques