How it works

Choose a page size and margins, then add sections. A section is one block of puzzles: a type, a count, a difficulty and how many print per page. Books can mix all four puzzle types, and sections print in the order you arrange them.

Running totals update as you go, so you can see roughly how many pages the book will run to before generating anything.

Puzzles are generated by algorithms running in your browser, spread across background threads so the page stays responsive. Progress counts finished puzzles. It is not an animation.

Each finished puzzle is then handed to a separate validator, written independently of the generator that made it:

• Sudoku and Samurai are solved from scratch and must have exactly one solution.
• Word searches are scanned to confirm every listed word really is in the grid.
• Mazes are solved with a fresh search that must reach the finish.

A puzzle that fails is regenerated from a new seed rather than shipped. The validation summary reports what actually passed.

The PDF is written in your browser. Grids, walls, solution paths and text are vector drawing operations, not images, so everything stays sharp when printed or zoomed.

Margins mirror for binding: the inside margin sits on the left of odd pages and the right of even pages. Page numbers are placed in a reserved footer band, so they cannot collide with a puzzle.

Every book has a seed. The same seed with the same settings rebuilds exactly the same puzzles, on any machine. That is useful for reprinting a book, or fixing a typo without regenerating everything.

Each new book starts from a fresh random seed drawn from your browser's cryptographic random number generator.