kdpbook.io

kdpbook.io review: an AI book studio built around Amazon KDP’s file rules

By Ashley Richmond. Reviewed October 2, 2026.

kdpbook.io is a browser-based AI book studio from THE VIBECODING AGENCY, a small Paris company founded by Arsène Huot. You describe a book in a sentence, or import your own manuscript, and the service plans it, writes it, illustrates it and typesets it. It then exports the files Amazon Kindle Direct Publishing asks for: an interior PDF, a full-wrap cover PDF, a Kindle EPUB and a listing sheet with a title, description and seven keywords. The vendor’s own shorthand is “Lovable for books”, and it says plainly that it is not affiliated with Lovable or with Amazon.

My view is cautiously positive. The product is aimed at one narrow job, KDP formatting, and it prices that job in a clear way. It is also brand new (the public launch was September 26, 2026), I did not run a book through it, and the output quality is something no desk review can judge.

What I checked

I read the live homepage, pricing page, press kit, about page, AI content policy, terms, privacy policy and legal notice. I looked at the free KDP spine width calculator, a vendor sample book page and the pricing screen as they render in a browser. I did not create an account, spend credits, generate a book, export a file or upload anything to KDP. The vendor’s YouTube demo could not be downloaded for inspection, so the screenshots here come from the public site, not from inside a logged-in session.

From a sentence to a book

The homepage puts a single prompt box front and center, with a book type chooser (Auto by default) and a language selector. The vendor describes four steps: describe or import, pick a book type and art style, watch the book build page by page, then edit, preview and export. There are 36 book types in eight families, including picture books, illustrated stories, novels, non-fiction guides, coloring books, activity and puzzle books, journals and comics. The vendor lists 40 illustration styles plus a custom style from a description or reference image, and 34 languages that KDP publishes.

Imported manuscripts can be Word, PDF, Markdown or plain text. The vendor says it keeps your words as written and only splits them into pages or chapters, which matters if you do not want an AI rewriting your book. EPUB import is not supported.

The KDP rules part

This is the clearest selling point. The site says its layout engine applies trim size, margins, bleed, spine width, barcode area and page limits by code rather than by AI, checked against KDP Help. The free spine width calculator is a public example: it takes binding, paper, trim size and page count and returns spine width, whether spine text fits and full cover dimensions. I only checked that one calculator, and I did not verify its numbers against Amazon’s own tool.

Exports are described as free of credits. Coloring, puzzle, activity and journal books are print only and have no Kindle file. Characters are kept consistent through reference sheets reused on every illustration, and there is a 3D book preview. I could not test any of this.

Pricing

Billing is credit based. New accounts get 2,000 free credits once, with no card. The vendor estimates a default 32-page picture book at about 1,624 credits, roughly $16 at the Starter rate, and a 336-page novel at about 5,377 credits. A credit estimate is shown before each generation, the estimate is held, and unused credits are released. Paid plans are Starter at $25 a month, Author at $49 and Studio at $99, with 2,500, 5,500 and 12,000 monthly credits, and yearly billing costs ten months instead of twelve. Credit packs from $10 to $500 are sold to subscribers only.

The licensing split deserves a close read. Free-plan books carry a “kdpbook.io preview” watermark, are shared in the community and, per the vendor’s AI content policy, are not licensed for sale. A paid plan adds a commercial license and clean files. That means the free tier is a trial, not a way to publish.

AI disclosure and approval are still yours

The vendor states that text and images it generates count as AI-generated content under KDP’s guidelines and must be disclosed when you publish. Its export sheet suggests the disclosure answers, but you are responsible for what you tell KDP. The site also says no tool can promise KDP will approve a book, and it makes no claim about sales or earnings. I agree with that framing. Check KDP’s current rules yourself before publishing, because those rules change.

Company and data

The company details are unusually easy to find. The legal notice lists the Paris registration, a share capital of one euro and the hosting providers. The privacy policy, updated September 30, 2026, names Stripe for payments and describes account, book, billing, anti-abuse and analytics data. It also describes an ad-measurement pixel from OpenAI that applies when you sign up or buy, with opt-in rules in some regions. Your prompts and manuscripts are sent to the vendor’s AI providers to produce the book. If your manuscript is confidential, read the privacy policy first.

Who it suits

It fits self-publishers who want KDP-ready print and Kindle files for low-content and illustrated books, and who accept that the content is AI generated. It is a poor fit if you need a human-written novel polished by an editor, a mobile app, or a public API. The press kit says there is no mobile app and no public API.

Where I would be careful

It is a very young product from a tiny company, with no independent reviews I could find. The costs scale with the length and illustration count of each book, so a long illustrated title can use a large share of a monthly plan. KDP also limits how many titles an account can publish; the vendor states a weekly cap, which I did not verify. Quality, consistency and acceptance by KDP were not tested here.

Bottom line

kdpbook.io is a focused answer to the tedious part of self-publishing on KDP, with transparent credit pricing and a clear free trial. Try the free credits and the free calculators first, read the licensing and AI disclosure terms, and check a sample export against KDP’s own previewer. My 3.5 out of 5 is a desk-research opinion, not a measured result.

Sources

Official site; pricing; press kit; about; AI content policy; terms; privacy policy; legal notice; spine width calculator; Product Hunt listing.