llms.txt
# Once Books
> Personalised children’s books where your child stays recognisable on every page: the same face, the same art style, from the cover to the last page.
Once Books creates personalised children's picture books where the same characters
stay recognisable across every page, in one consistent art style.
## What makes it different
Image models are stateless: page 4's bear is not page 3's bear. Once Books solves
this with a Consistency Engine: locked character descriptions, approved reference
images used for conditioning, an art style frozen onto each book, and deterministic
seeds. The result is a book that reads as one book rather than a set of related pictures.
## Key pages
- [How it works](https://www.oncebooks.com/how-it-works): the avatar → style → story → book flow
- [Stories](https://www.oncebooks.com/stories): eight ready-made stories a child can star in
- [Art styles](https://www.oncebooks.com/styles): the illustration styles a book can be drawn in
- [Sample books](https://www.oncebooks.com/books): full sample books, page by page
- [Free printable tools](https://www.oncebooks.com/tools): free browser generators for word search, sudoku, crosswords and 3D spatial puzzles, plus lined paper, printable calendars and a KDP cover calculator, no sign-up
- [Pricing](https://www.oncebooks.com/pricing): the formats, a digital PDF today with print coming soon
- [Examples](https://www.oncebooks.com/examples): a sample book and the story themes on offer
- [Answers](https://www.oncebooks.com/answers): direct answers to common pre-purchase questions
- [Child safety](https://www.oncebooks.com/child-safety): how uploaded photographs are handled
- [Compare](https://www.oncebooks.com/compare): how Once Books differs from other personalised-book services
- [Glossary](https://www.oncebooks.com/glossary): the terms used here, defined. Character Sheet, Look, trim, bleed
- [Help centre](https://www.oncebooks.com/help): step-by-step articles for making, printing and sharing a book
- [Blog](https://www.oncebooks.com/blog): guides and product notes, including the KDP publishing walkthroughs
- [About](https://www.oncebooks.com/about): who makes Once Books and why
- [For authors](https://www.oncebooks.com/for-authors): the print-ready export path for self-publishers
- [For teachers](https://www.oncebooks.com/for-teachers): classroom use, school networks and safeguarding
- [Illustration cost](https://www.oncebooks.com/illustration-cost): what children's-book illustration normally costs, with sources
## Word search publishing (KDP)
Once Books also runs Publisher Studio, a separate tool for Amazon KDP self-publishers
who make and sell low-content word-search books. It generates hundreds of puzzles from
an AI-assisted word bank, de-duplicates them, and exports a print-ready 300 DPI interior
PDF and a separate answer-key PDF at any KDP trim, for a one-time $4.99 per-project unlock.
- [Free word search generator](https://www.oncebooks.com/tools/word-search-generator): make one printable puzzle and answer key in the browser, no sign-up
- [Word search by theme](https://www.oncebooks.com/word-search): free printable puzzles across dozens of themes
- [KDP word-search maker](https://www.oncebooks.com/kdp-word-search-maker): the paid studio, generate once and export every trim
- [How to make and sell word search books on KDP](https://www.oncebooks.com/blog/how-to-make-and-sell-word-search-books-on-kdp): the full publishing guide
## Sudoku publishing (KDP)
Publisher Studio also makes sudoku books. It generates hundreds of graded 9x9 puzzles
across a difficulty curve (easy to evil), each verified to have exactly one solution,
and exports a print-ready 300 DPI interior PDF and a separate solutions PDF at any KDP
trim, for the same one-time $4.99 per-project unlock. No AI: boards are generated by a
deterministic algorithm with a unique-solution guarantee.
- [Free sudoku generator](https://www.oncebooks.com/tools/sudoku-generator): make one printable puzzle and its solution in the browser, no sign-up
- [Sudoku by difficulty](https://www.oncebooks.com/sudoku): free printable puzzles from easy to evil, plus large-print and for-kids
- [KDP sudoku maker](https://www.oncebooks.com/kdp-sudoku-maker): the paid studio, generate a graded book once and export every trim
## Crossword publishing (KDP)
Publisher Studio also makes crossword books. It drafts a themed clue bank, interlocks
the answers across and down into a numbered grid, and exports a print-ready 300 DPI
interior PDF and a separate answer-key PDF at any KDP trim, for the same one-time
$4.99 per-project unlock.
- [Free crossword generator](https://www.oncebooks.com/tools/crossword-generator): type clues and print a puzzle plus its answer key, no sign-up
- [Crosswords by theme](https://www.oncebooks.com/crossword): free printable puzzles with answers across dozens of themes
- [KDP crossword maker](https://www.oncebooks.com/kdp-crossword-maker): the paid studio, generate a book once and export every trim
## 3D spatial puzzle publishing (KDP)
Publisher Studio also makes 3D spatial-reasoning books. It generates graded figures
worker-side (no AI): isometric stacks of cubes to count, and block solids to match to
their top, front and side views or to build from those views. Every answer is computed
from the same figure the reader sees, so the printed answer key can never disagree, and it
exports a print-ready 300 DPI interior PDF and a separate answer-key PDF at any KDP trim,
for the same one-time $4.99 per-project unlock.
- [Free spatial puzzle generator](https://www.oncebooks.com/tools/spatial-puzzle-generator): count the cubes, draw the views or build the solid, and print the answer, no sign-up
- [Spatial puzzles by type](https://www.oncebooks.com/spatial-puzzles): free printable puzzles across cube counting, view drawing and difficulty grades
- [KDP spatial puzzle maker](https://www.oncebooks.com/kdp-spatial-puzzle-maker): the paid studio, generate a graded book once and export every trim
- [How to make and sell spatial puzzle books on KDP](https://www.oncebooks.com/blog/how-to-make-and-sell-spatial-puzzle-books-on-kdp): the full publishing guide
## More puzzle books (KDP)
Publisher Studio makes the same print-ready books for every other puzzle type below. Each one is
generated worker-side with a correctness guarantee (a unique solution, an exhaustive answer, or a
proven round-trip), exported as a 300 DPI interior PDF and a separate answer-key PDF at any KDP
trim, for the same one-time $4.99 per-project unlock. Each has a free in-browser generator
to try first.
- [Free Mazes generator](https://www.oncebooks.com/tools/maze-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Mazes](https://www.oncebooks.com/maze) and the [KDP Mazes maker](https://www.oncebooks.com/kdp-maze-maker)
- [Free Nonograms generator](https://www.oncebooks.com/tools/nonogram-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Nonograms](https://www.oncebooks.com/nonogram) and the [KDP Nonograms maker](https://www.oncebooks.com/kdp-nonogram-maker)
- [Free Binairo generator](https://www.oncebooks.com/tools/binairo-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Binairo](https://www.oncebooks.com/binairo) and the [KDP Binairo maker](https://www.oncebooks.com/kdp-binairo-maker)
- [Free Futoshiki generator](https://www.oncebooks.com/tools/futoshiki-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Futoshiki](https://www.oncebooks.com/futoshiki) and the [KDP Futoshiki maker](https://www.oncebooks.com/kdp-futoshiki-maker)
- [Free Skyscrapers generator](https://www.oncebooks.com/tools/skyscrapers-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Skyscrapers](https://www.oncebooks.com/skyscrapers) and the [KDP Skyscrapers maker](https://www.oncebooks.com/kdp-skyscrapers-maker)
- [Free Kakurasu generator](https://www.oncebooks.com/tools/kakurasu-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Kakurasu](https://www.oncebooks.com/kakurasu) and the [KDP Kakurasu maker](https://www.oncebooks.com/kdp-kakurasu-maker)
- [Free Kakuro generator](https://www.oncebooks.com/tools/kakuro-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Kakuro](https://www.oncebooks.com/kakuro) and the [KDP Kakuro maker](https://www.oncebooks.com/kdp-kakuro-maker)
- [Free Magic Square generator](https://www.oncebooks.com/tools/magic-square-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Magic Square](https://www.oncebooks.com/magic-square) and the [KDP Magic Square maker](https://www.oncebooks.com/kdp-magic-square-maker)
- [Free Number Pyramid generator](https://www.oncebooks.com/tools/number-pyramid-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Number Pyramid](https://www.oncebooks.com/number-pyramid) and the [KDP Number Pyramid maker](https://www.oncebooks.com/kdp-number-pyramid-maker)
- [Free Calcudoku generator](https://www.oncebooks.com/tools/calcudoku-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Calcudoku](https://www.oncebooks.com/calcudoku) and the [KDP Calcudoku maker](https://www.oncebooks.com/kdp-calcudoku-maker)
- [Free Number Blocks generator](https://www.oncebooks.com/tools/number-blocks-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Number Blocks](https://www.oncebooks.com/number-blocks) and the [KDP Number Blocks maker](https://www.oncebooks.com/kdp-number-blocks-maker)
- [Free Straights generator](https://www.oncebooks.com/tools/straights-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Straights](https://www.oncebooks.com/straights) and the [KDP Straights maker](https://www.oncebooks.com/kdp-straights-maker)
- [Free Hitori generator](https://www.oncebooks.com/tools/hitori-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Hitori](https://www.oncebooks.com/hitori) and the [KDP Hitori maker](https://www.oncebooks.com/kdp-hitori-maker)
- [Free Fill-in generator](https://www.oncebooks.com/tools/fill-in-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Fill-in](https://www.oncebooks.com/fill-in) and the [KDP Fill-in maker](https://www.oncebooks.com/kdp-fill-in-maker)
- [Free Codeword generator](https://www.oncebooks.com/tools/codeword-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Codeword](https://www.oncebooks.com/codeword) and the [KDP Codeword maker](https://www.oncebooks.com/kdp-codeword-maker)
- [Free Word Wheel generator](https://www.oncebooks.com/tools/word-wheel-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Word Wheel](https://www.oncebooks.com/word-wheel) and the [KDP Word Wheel maker](https://www.oncebooks.com/kdp-word-wheel-maker)
- [Free Word Scramble generator](https://www.oncebooks.com/tools/word-scramble-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Word Scramble](https://www.oncebooks.com/word-scramble) and the [KDP Word Scramble maker](https://www.oncebooks.com/kdp-word-scramble-maker)
- [Free Missing Vowels generator](https://www.oncebooks.com/tools/missing-vowels-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Missing Vowels](https://www.oncebooks.com/missing-vowels) and the [KDP Missing Vowels maker](https://www.oncebooks.com/kdp-missing-vowels-maker)
- [Free Cryptogram generator](https://www.oncebooks.com/tools/cryptogram-generator): make one printable puzzle and its answer in the browser, no sign-up; also [printable Cryptogram](https://www.oncebooks.com/cryptogram) and the [KDP Cryptogram maker](https://www.oncebooks.com/kdp-cryptogram-maker)
## Journal and planner publishing (KDP)
Publisher Studio also makes low-content books: journals and planners. There is no
generation step here, the plan is the book. You choose the interior directly:
lined, dot grid or graph pages and guided prompts for a journal, or a dated or
undated daily, weekly or monthly layout for a planner, with a year-at-a-glance and
habit-tracker pages. It exports a print-ready 300 DPI interior PDF and a matching
cover at any KDP trim, for the same one-time $4.99 per-project unlock. Journals and
planners carry no puzzles, so there is no answer key. You can sell the finished
book on Amazon KDP, Etsy, Lulu, IngramSpark or your own printer.
- [Free lined paper generator](https://www.oncebooks.com/tools/lined-paper-generator): print lined, dot grid, graph or a guided journal page in the browser, no sign-up
- [Free printable calendar and planner pages](https://www.oncebooks.com/tools/printable-calendar): print a month, a week or a day, dated or blank, no sign-up
- [KDP cover calculator](https://www.oncebooks.com/tools/kdp-cover-calculator): work out spine width and full wraparound cover size from your trim, paper and page count
- [Etsy mockup maker](https://www.oncebooks.com/tools/etsy-mockup-maker): turn the PDF you sell into up to 15 listing images in dozens of scenes (tablet, 3D cover, binder, home printer, framed print, desk, spread, close-up, page size) in the browser, no upload
- [Journals by ruling and prompt](https://www.oncebooks.com/journal): lined, dot grid and guided journal pages you can print or publish
- [Planners by layout](https://www.oncebooks.com/planner): daily, weekly and monthly layouts, dated or undated
- [KDP journal maker](https://www.oncebooks.com/journal-maker): the paid studio, build a journal once and export every trim
- [KDP planner maker](https://www.oncebooks.com/planner-maker): the paid studio, build a dated or undated planner once and export every trim
- [How to make and sell journals and notebooks](https://www.oncebooks.com/blog/how-to-make-and-sell-journals): the full publishing guide
- [How to make and sell planners on KDP](https://www.oncebooks.com/blog/how-to-make-and-sell-planners-on-kdp): the full publishing guide
## For agents
Every page on this site is also published as Markdown. Send `Accept: text/markdown`
and you get the same page as Markdown instead of HTML, roughly a twentieth of the
tokens, with the navigation, styling and scripts stripped out. The response carries
`Content-Type: text/markdown` and an `x-markdown-tokens` estimate so you can budget
before you read. Every page also links its Markdown twin from the HTML as
`<link rel="alternate" type="text/markdown">`, and the twins are fetchable directly
at `<page>.md` if you would rather ask for a URL than set a header. The whole
site is also concatenated into one file at https://www.oncebooks.com/llms-full.txt if you
would rather read everything in a single fetch.
## Contact
- Support: support@oncebooks.com
- Security: security@oncebooks.com
