Question 1

How hard are these expert sudoku puzzles?

Accepted Answer

The fewest givens and the longest deduction chains. Expect to need pencil marks throughout and to lean on pairs, triples, and box-line interactions. Still solvable by pure logic — no guessing is ever required. Each of the 12 puzzles in this set starts from about 24 given numbers.

Question 2

Does every puzzle have only one solution?

Accepted Answer

Yes, and that is checked rather than assumed. Clues are removed one at a time, and after each removal the puzzle is re-solved to confirm exactly one solution remains. If a removal would create a second solution, the clue goes back. A puzzle with two answers is not a harder puzzle — it is a broken one.

Question 3

Is there an answer key?

Accepted Answer

Yes. The last two pages of the PDF hold all 12 solutions, six to a page.

Question 4

Do I need to guess?

Accepted Answer

Never. Every puzzle here is solvable by logic alone. If you find yourself guessing, there is a deduction still available somewhere on the grid.

Question 5

Are these the same puzzles every time?

Accepted Answer

Yes. Each puzzle is generated from a fixed seed, so the file you download today is the same one you would download next year — which means a printed answer key never stops matching its puzzles.

2	empty	empty	empty	empty	9	empty	empty	4
5	empty	empty	empty	empty	4	6	empty	8
empty	empty	empty	empty	empty	empty	empty	empty	empty
6	empty	3	empty	empty	empty	empty	empty	empty
7	empty	empty	6	empty	5	empty	empty	empty
empty	5	8	empty	1	empty	empty	7	empty
empty	4	empty	empty	6	empty	empty	1	empty
empty	1	empty	8	empty	3	empty	empty	7
empty	empty	5	empty	empty	empty	empty	empty	empty

12 expert sudoku puzzles, with answers.

Puzzle 1 from this set

What makes these expert

Every puzzle has exactly one solution

Other difficulties

Common questions

Printing