---
title: "Hard sudoku: free printable with solutions"
description: "Free printable hard sudoku with the solution. Around thirty starting numbers for a real challenge, still exactly one solution, answer key included."
source: "https://www.oncebooks.com/sudoku/hard"
---

1. [Home](https://www.oncebooks.com/)
2. [Sudoku](https://www.oncebooks.com/sudoku)
3. Hard

Free printable

# Hard sudoku

Hard sudoku gives you fewer numbers to begin with, so the deductions run deeper and the solve takes longer. It is still fair: every board has exactly one solution, verified by our solver. The full answer prints on the second page when you want to check.

PuzzleDesign

Difficulty

EasyMediumHardExtremeEvil

Higher grades need harder solving techniques, not just fewer given numbers.

27 given numbers

Hardest step to solve: Locked candidates

Layout

SymmetricRandom

Symmetric gives the classic newspaper look.

Theme

ClassicBoldSoftShadedNavyIndigoSkyTealEmeraldForestPlumBerryCrimsonEmberAmberCocoa

**Customise colours**

Numbers

Cell lines

Box lines

Page background

Style

StandardClean

Clean drops the title band and footer, leaving the grid.

Generate puzzlePrint / save PDF

Two pages: the puzzle and its solution. Every board has exactly one solution, generated by the same engine as our KDP studio.

## Want the whole book?

This makes one puzzle. Sign up to turn it into a full sudoku book for Amazon KDP: hundreds of graded puzzles at any trim, as print-ready PDFs. We carry your difficulty into the studio.

[Build the full book](https://app.oncebooks.com/publisher-studio/sudoku/edit?from=sudoku&v=2&s=eyJkaWZmaWN1bHR5IjoiSEFSRCIsImNvbG9yVGhlbWUiOnsidGhlbWVJZCI6ImNsYXNzaWMiLCJvdmVycmlkZXMiOnt9fX0)

Free to build · pay once to export

Preview

The puzzle and its solution, as they print.

Hide the preview

- Sudoku Hard

  1

  Puzzle
- Sudoku Hard · Solution

  2

  Solution

Generate puzzlePrint / save PDF

## Making a whole sudoku book?

This page makes one puzzle. To publish a book on Amazon KDP, the [KDP sudoku maker](https://www.oncebooks.com/kdp-sudoku-maker) generates hundreds of graded puzzles at any trim, as a print-ready 300 DPI interior and solutions PDF. Generate once, export unlimited sizes.

## More printable sudoku

- [Easy sudoku](https://www.oncebooks.com/sudoku/easy)
- [Medium sudoku](https://www.oncebooks.com/sudoku/medium)
- [Expert sudoku](https://www.oncebooks.com/sudoku/expert)
- [Evil sudoku](https://www.oncebooks.com/sudoku/evil)
- [Large print sudoku](https://www.oncebooks.com/sudoku/large-print)
- [Printable sudoku](https://www.oncebooks.com/sudoku/printable)

[See every printable sudoku](https://www.oncebooks.com/sudoku)

## Questions

**Is this hard sudoku free to print?**

Yes. Generate the puzzle above and print it with its solution, at no cost and with no sign-up. It is free for classroom, home and personal use.

**Does every hard sudoku board have one solution?**

Yes. Every board is generated and verified to have exactly one solution, so a puzzle is never ambiguous or unsolvable. The full solution prints on the second page.

**Can I make a sudoku book to sell on KDP?**

Yes. The free tool makes one puzzle. The KDP sudoku maker generates hundreds of graded puzzles at any KDP trim, as a print-ready 300 DPI interior and solutions PDF, so you can publish a book.