vøiddoutilities

kdp · puzzle books

Puzzle books for KDP, ready to upload.

Sudoku, killer sudoku, calcudoku, futoshiki, word search, maze, kakuro, fill in, cryptogram, word scramble and number search books, or a variety book of several kinds, each with the interior PDF, the full wrap cover and a signed check of both files against KDP’s paperback specs. From $3.30 a book, no subscription.

Coloring books too: 11 to 50 designs drawn for each book, same credits.

The full wrap cover of a sample book: the back with a description and a puzzle from inside, the spine with the title, and the front.
sample book, cover as delivered · back · spine · front · 116 pages · 8.5 × 11 in

500 credits a book24 to 470 pages5 trim sizes · 3 paperslarge print optionready in 3 to 20 s

what you download

One ZIP per book. Upload two files.

  • interior.pdfThe inside pages: title page, how-to page, puzzles, full solutions. Fonts embedded, margins and gutter set for the page count.
  • cover.pdfBack, spine and front on one page with 0.125 in bleed. Spine width from KDP’s formula for your page count and paper.
  • check-report.pdfOur check of both files against KDP’s paperback specs, signed. Anyone can confirm it is genuine on the verify page.
  • listing.txtTitle, subtitle, description, seven keyword ideas and the print options to pick on KDP.
  • preview/Six images of real pages for your listing, A+ content or posts.
  • README.txtThe upload steps, the book seed and the report id.
Front cover of the sample sudoku bookA puzzle page from the sample sudoku bookA solutions page from the sample sudoku book
Sudoku150 puzzles · 116 pages · 8.5 × 11
Front cover of the sample word search bookA puzzle page from the sample word search bookA solutions page from the sample word search book
Word search66 puzzles · 86 pages · 8.5 × 11
Front cover of the sample maze bookA maze page from the sample maze bookA solutions page from the sample maze book
Mazes80 mazes · 104 pages · 8 × 10

Every image on this page is a page our program made for a sample book, shown as delivered. Each puzzle is checked by a second, independent program before it is printed: one solution per sudoku, per killer sudoku, per calcudoku, per futoshiki, per kakuro and per fill in grid, each word or number exactly once per word or number search, one route per maze, every cryptogram decoded again, every word scramble re-spelled from its letters.

More book types: killer sudoku · calcudoku · futoshiki · kakuro · cryptograms · word scrambles · number search · fill in · variety books · Christmas books

One book, six covers

The same large print word search book in six of its 33 covers: 11 colors and 3 layouts. Pick the color and layout on the form, so your series looks like no one else’s. Left alone, a book gets its kind’s own color with the puzzle above the title, the first cover here.

  • Front cover of the sample word search book in forest green, the puzzle above the titleforest · puzzle above
  • Front cover of the sample word search book in plum, the title on a card over the puzzleplum · title card
  • Front cover of the sample word search book in ochre, the title above the puzzleochre · title above
  • Front cover of the sample word search book in teal, the title on a card over the puzzleteal · title card
  • Front cover of the sample word search book in crimson, the puzzle above the titlecrimson · puzzle above
  • Front cover of the sample word search book in slate, the title above the puzzleslate · title above

make a book · 500 credits

Choose the book. Download the files.

the book

 

Bigger grids and type; fewer puzzles per page. What changes

Up to 70 characters. Printed on the cover, the spine and the title page.

Subtitle, author, cover, themes, seed

Left empty, it says how many puzzles, the level and “With Solutions”.

Give a series its own color, so your covers look like no one else’s. Each kind has its own color by default.

Where the title sits on the front. With the color, it gives a series a cover of its own.

The same seed and settings make exactly the same book again. Left empty, every book is new.

your api key

Books are paid with book credits on an API key. Buy book credits and the key is filled in here for you.

 

Your book appears here: the ZIP to download, its page count and the link to its signed report.

free · no key · 20 a day

Free tools for any KDP paperback.

Spine width and cover size

Full tables for all 16 trim sizes, white and cream paper: KDP cover sizes.

Check your files before you upload

Up to 10 MB for both files together. Checked: page size, page count, fonts embedded, text and art inside the margins and gutter, image resolution, small text, line weight, runs of blank pages, encryption, cover size, spine text and the barcode area. The files are deleted after the check; only the signed report is kept. Our 10 sample pages fail one check, the page count: a KDP paperback needs at least 24 pages. What each rule means, in KDP’s words: why KDP rejects a puzzle book.

book credits · one-time · never expire

$5 a book, or $3.30 in the big pack.

the guarantee

If KDP rejects a book’s files within 30 days of making it, write to data@voiddo.com with the report id and KDP’s message, and the book’s 500 credits go back to your key. Unused credits can be refunded within 14 days of purchase.

Prices side by side
vøiddoKDP Builder
Smallest pack$15 for 3 books, $5.00 a book$8.99 for 100 credits, listed as “≈ 1 puzzle book”
Largest pack$99 for 30 books, $3.30 a book$89.99 for 1,500 credits, listed as “≈ 10–15 puzzle books”, $6.00 to $9.00 a book
Credit cost of a book500 credits, always“~100–150 credits per book”
CoverTypeset by our program from the book’s own puzzles; no pictures“AI generates a professional cover”

KDP Builder figures and quotes from kdpbuilder.com/pricing and its puzzle book page, read on 21 October 2026. Their per-book price is their own estimate in credits; check their page for today’s numbers.

Questions

Will KDP accept the files?

Each book passes our own check against KDP’s published paperback specs before you can download it: page size, page count, embedded fonts, margins and gutter for the page count, line weight, blank pages, cover size and spine. If KDP still rejects the files within 30 days, the book’s credits come back.

Do I answer “yes” to KDP’s AI-generated content question?

Here are the facts, so you can answer from KDP’s own definitions. The puzzles, the solutions, the page layout and the cover design are made by ordinary computer programs, not by an AI model, and the covers have no pictures. The fixed wording every book shares (the how-to page, the back cover text, the listing description) and the word search theme lists were drafted with an AI writing tool when the program was written. The choice and the responsibility are yours as the publisher.

Can I sell the books under my own name?

Yes. Put your name or imprint in the author field. Every book without a seed gets new puzzles; the same seed and settings make the same book again, which is how you can rebuild a book later.

Will my covers look like other people’s?

Left as they are, books of one kind share the cover’s color and layout, with your title, subtitle and name on the front and the spine. Pick one of 11 cover colors and one of 3 layouts on the form, under Subtitle, author, cover, so your series stands apart from other people’s books. Each kind has its own color by default.

Do I need an ISBN?

No. KDP gives a free ISBN to paperbacks, and puzzle books with full solutions are not treated as low-content books, so the free ISBN is available. listing.txt says which options to pick.

Which sizes and page counts?

Trim sizes 6 × 9, 7 × 10, 8 × 10, 8.5 × 11 in and A4, white, cream or groundwood paper, 24 to 470 pages. The form shows how many puzzles fit for each choice.

Can I use the API instead of this page?

Yes: POST https://data.voiddo.com/v1/kdp_puzzle_book with the same fields as JSON and your key in the Authorization header. The spine calculator and the file check are kdp_spine_calc and kdp_preflight. See the API docs.