SuuudokuuuPrintable Hell Sudoku PDF (17 Clues)
Updated
Every puzzle in this booklet carries exactly 17 clues, the proven minimum for a sudoku with one unique solution, drawn from our bundled and independently verified 17-clue corpus rather than generated fresh. Our published sample of 40 boards measures the tier at SE 6.7 to 7.8, with the AIC as the most common hardest step. See the 17-clue guide for what the clue count does and does not tell you here.
| c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c9 | |
|---|---|---|---|---|---|---|---|---|---|
| r1 | |||||||||
| r2 | 1 | ||||||||
| r3 | 2 | 3 | 4 | ||||||
| r4 | 5 | 6 | |||||||
| r5 | 7 | 8 | |||||||
| r6 | 8 | 1 | 7 | ||||||
| r7 | 8 | ||||||||
| r8 | 3 | 6 | |||||||
| r9 | 9 | 5 | 3 |
- 16 puzzles
- 9 pages
- 43 KB PDF, US Letter
- Solutions included on the last pages
What is inside the booklet
With so few givens, the printed grid looks almost empty at first glance — the 16 puzzles print 4 to a page with generous cell size specifically so there is room to track candidates by hand across a long chain. The final pages hold the completed grids, which is close to essential at this tier: verifying a chain of eliminations by eye is slow, and a printed key lets you confirm the end state without re-deriving the whole path.
How the puzzles are verified
Every 17-clue puzzle in this booklet comes from a bundled corpus that Suuudokuuu checks with two independent solving algorithms — a Dancing Links exact-cover solver and a typed-array bitmask solver — before it ships, rather than generating a fresh grid and hoping the clue count still leaves a unique solution. That is deliberate: seventeen clues is the smallest mathematically proven count that can still guarantee one solution, so there is no safety margin for a generator to get it slightly wrong. Each puzzle is also rated on the SE scale as the corpus is packed, and anything that rates too low for the tier is dropped — the clue count alone would not be enough to promise a hard puzzle. Printing from a pre-verified source means every puzzle here is guaranteed solvable before you ever pick up a pencil.
Where to go next
Not ready for chains on paper yet? Step back to the printable Nightmare sudoku booklet for the same chain reasoning with more of the grid filled in, or to printable Hard sudoku for fish and wings without chain-length reasoning, or play Hell on a screen at the Hell sudoku lander, where the same 17-clue corpus powers every puzzle.
Printable Hell Sudoku FAQ
Is the printable Hell sudoku PDF free?
Yes, with no account and no watermark, and every puzzle’s solved grid is included at the back.
Are these real 17-clue puzzles?
Yes. Every puzzle is drawn from a bundled corpus checked by two independent solving algorithms and rated on the SE scale before it is packed, rather than generated fresh at print time.
Does 17 clues mean these puzzles are the hardest possible?
No. Clue count and difficulty are separate facts — see the 17-clue sudoku guide. These puzzles are hard because they are filtered by SE rating, not because of the clue count alone.
How many puzzles are in the printable Hell sudoku PDF?
16 puzzles across 9 pages, four to a page, with the solved grids at the back.