Youbooks

Youbooks drafts non-fiction books of up to 300,000 words from your own sources, grounding each chapter in uploaded research. You can also train a model on your writing samples so the book matches your voice.

You add PDFs, documents, transcripts or notes, and Youbooks can search the web for extra context, or you can draft from a brief alone. The voice model needs 20K to 200K words of your writing to fine-tune; otherwise an editorial default voice is used.

A short four-question fit check helps you decide whether it suits your project, and the site shows sample books and a roadmap. The interface is offered in more than a dozen languages, including German, French, Spanish and Japanese. Pricing is not shown on the pages checked.