answer key switched on
Printable sudoku with answers: puzzles and full solutions in one PDF
Each run can carry its own answer key: the puzzles first, then a solution section at the back, with each grid labelled with the same ID as the puzzle it solves.
Set a run with answers
answers are on here; untick the box to leave them out
1–60 · the solver checks each puzzle for a single solution before adding it
This sample switches to your own puzzles when the run finishes.
How the PDF lays out the answer key
Solutions and puzzles sit on separate pages. Your PDF runs all the puzzle pages first, however many your layout needs, and then starts a fresh section headed answer key. If you hand sheets out, print the document and keep the back half, and nobody sees the answer to the grid in front of them.
A code matches each solution to its puzzle. Each puzzle prints a six-character code under its grid, along with its difficulty and starting clue count. Its solution prints the same code followed by the word “solution”. You can shuffle the pages, split them between two rooms and come back a month later, and the codes still line up. If the key goes missing, the same code fetches the answer on the answer lookup page.
The key copies the layout of the puzzles, so two puzzles per page gives two solutions per page. For solution grids large enough to check quickly, set the layout to one or two per page.
Why the printed answer is the right one
The generator builds a complete, valid grid first, and the puzzle is what remains after it removes clues. The answer key you print is that original grid.
The removal rule prevents a second valid answer. After each removal, a solver counts the solutions of the remaining grid, stopping at two. If it finds two, the generator puts the clue back. You can complete the printed puzzle only one way, and the key at the back of your PDF shows that way.
Sudoku with answers: questions
Where do the answers appear in the PDF?
In their own section after the puzzle pages, on separate sheets from the puzzles they solve. You can hand out the puzzle pages and keep the key back, and nobody glimpses an answer by accident.
How do I match a solution to its puzzle?
Each puzzle has a six-character code printed under its grid, next to its difficulty and clue count. Its solution carries the same code, so "#K7M2A9 solution" answers puzzle #K7M2A9 however you shuffle the pages.
Can I print the puzzles without the answer key?
Yes. Leave "Include answers" unticked and the PDF contains puzzle pages only. That is the default everywhere except this page. You can also generate with answers and print the first half of the document, since the key comes last.
Are the answers guaranteed correct?
Yes. The generator builds a complete, valid grid first and then removes clues from it, so the printed answer is the grid the puzzle came from. It removes a clue only when the puzzle still has a single solution, so no other grid fits.
Can I get the answer key at a bigger size?
Set puzzles per page to 1 or 2. The key uses the same layout as the puzzle section, so a one-per-page run gives you full-size solution grids you can check at a glance.
Pick a difficulty for your answer-key set
The answer key works the same at every level. You will use it most on hard and expert grids, where one wrong entry can hide for forty moves.
- Easy printable sudoku38–45 cluesPlenty of clues, and a solving path you can find by scanning alone.typical solve: 5–10 minutes
- Medium printable sudoku30–37 cluesThe everyday sudoku, at the level a newspaper prints midweek.typical solve: 10–20 minutes
- Hard printable sudoku25–29 cluesSparse grids that open up once you reason about where each digit cannot go.typical solve: 20–40 minutes
- Expert printable sudoku20–24 cluesAbout a quarter of the grid filled in, and one solution to reach.typical solve: 40 minutes to over an hour
Back to the free printable sudoku generator or browse all printable sudoku levels.