Clue count - the number of digits already placed when you start - is one of the most reliable predictors of Sudoku difficulty. Lower counts demand more advanced techniques; higher counts reward fast scanning. Pick a band below to play puzzles at exactly that clue count.
For standard 9×9 Sudoku, the relationship is roughly:
Clue position also matters: two puzzles with the same clue count can require different techniques depending on where the givens cluster. Our difficulty rating uses both count and required technique.
Most Sudoku apps and books label puzzles only by difficulty bucket - easy, medium, hard. Clue count gives you a more precise dial. If you have outgrown medium but find hard frustrating, dropping from 30 clues to 28 is a smaller, more incremental step than jumping from medium to hard. The bands below let you climb the difficulty curve at your own pace.
The following bands are available in our collection, each backed by hand-verified puzzles or, in the 17-clue case, a curated showcase of famous examples.
17, proven in 2012 by McGuire, Tugemann, and Civario at University College Dublin. No 16-clue Sudoku has a unique solution. See our /sudoku-17-clue page for the full story.
There is no fixed maximum, but valid puzzles typically have between 17 and roughly 50 clues. Above 50 clues there is so little for the solver to do that the puzzle stops being interesting. Most published Sudoku fall between 22 and 35 clues.
On average yes, but not always. Two puzzles with the same clue count can require very different techniques depending on where the clues are placed. We sort puzzles by both clue count and required technique to give an accurate difficulty signal.
We publish a clue-count page when the band has enough hand-verified puzzles to make a meaningful collection - typically at least 17 puzzles. Counts with very few puzzles in our database are not yet broken out.
Yes - pick the matching band from the list above. Each page lets you page through every puzzle in our collection at that exact clue count.
Most newspaper Sudoku fall between 28 and 32 clues, with 30 being the canonical "medium" target. See our /sudoku-30-clue page for that exact band.
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