PaperKind Printables puzzles · Hard · 9×9
Hard Sudoku · 1
NameTime
Fill every empty square so that each row, each column and each 3×3 box contains the numbers 1 to 9 exactly once.
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Hard Sudoku · printable with solutions
Hard Sudoku puzzles for a real challenge.
Sparse 9×9 grids that reward patience and careful notes. Each still has exactly one solution.
At a glance
Who hard sudoku suits
Suitable for: Experienced solvers comfortable with pencil marks and looking for longer puzzles.
Starting clues: Hard 9×9 puzzles start with about 26 of 81 squares filled.
Every puzzle has exactly one solution, checked when it is created.
Printable puzzles
Hard Sudoku to print
Solutions stay hidden until you choose Show solution. Print the puzzle and solution separately.
PaperKind Printables puzzles · Hard · 9×9Solution
Hard Sudoku · 1 — solution
Completed grid. Bold numbers were the starting clues.
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PaperKind Printables puzzles · Hard · 9×9
Hard Sudoku · 2
NameTime
Fill every empty square so that each row, each column and each 3×3 box contains the numbers 1 to 9 exactly once.
71855487896532479197832643
PaperKind Printables puzzles · Hard · 9×9Solution
Hard Sudoku · 2 — solution
Completed grid. Bold numbers were the starting clues.
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Hard Sudoku
Techniques worth knowing
Pointing pairs: if a number's only options inside a box lie in one row, that number cannot appear elsewhere in that row. Hidden singles: a number may have only one possible square in a row, even if that square has several candidates.
Keep your pencil marks tidy and complete. Hard puzzles often turn on noticing one small pattern, which is much easier when the notes are accurate.
Hard Sudoku
A note on difficulty
PaperKind Printables grades puzzles by the number of starting clues. Clue count is a useful guide but not a perfect one, so two hard puzzles may feel quite different. If one is slow going, take a break and come back with fresh eyes.
Other levels
More Sudoku
Kids Sudoku4×4 puzzles start with about 8 of 16 squares filled; 6×6 puzzles start with about 20 of 36.Easy SudokuEasy 9×9 puzzles start with about 38 of 81 squares filled.Medium SudokuMedium 9×9 puzzles start with about 32 of 81 squares filled.Sudoku generatorMake a fresh puzzle at any level, with its solution.
Last reviewed: 24 September 2026
Questions
Frequently asked questions
By the number of starting clues — about 26 for hard. This is a practical guide rather than a precise measure of the techniques needed.
Yes. Use Show solution to reveal the completed grid on screen, or print the solution separately.