Free tools · Ebooks and book files
EPUB checker
Drop in your EPUB and see what the stores will object to before they tell you: a missing cover or contents, links that go nowhere, pages that aren't well-formed, images over Apple's limit, and the body-text styles KDP asks you to leave to the reader. Every problem is explained in plain English, with which store it matters for.
It's checked in your browser. Your book isn't uploaded to Bervet and nothing is kept. Free for members.
No file to hand? (an EPUB of three chapters from The Signal by R. S. Breed).
What it checks
- The EPUB's structure, as the W3C EPUB 3.3 standard sets it out: the mimetype file, the package, every file listed and present.
- Title, author, language and identifier, and whether an ISBN in the file is a real one.
- A cover inside the book (KDP and Google Play both ask for one), and that it's big enough.
- The table of contents: there, complete, in reading order, every link working (KDP's navigation guidelines).
- Every page well-formed, every link and image found, nothing loaded from the internet, no JavaScript.
- Images against Apple's pixel limit, and alt text on every image.
- The styles KDP's text guidelines ask you to leave to the reader: body text size, line spacing, colour, margins.
- Accessibility, as the W3C's EPUB Accessibility standard sets it out: the details that say who the book works for (access mode, features, hazards, a summary), headings that don't skip a level, and page numbers to jump to when the book reproduces a print edition.
Store rules checked 5 October 2026 on KDP's, Apple's, Google Play's, Kobo's and B&N's own pages.
What it doesn't
It isn't EPUBCheck, the W3C's full validator. Apple and Google Play require a file that passes it, and Kobo runs it on every upload, so run EPUBCheck too. It can't see how your book looks: KDP recommends opening it in Kindle Previewer before you upload.
Starting from a Word file? Make your book files builds an EPUB made to these rules; add your cover and it should pass them.
Written a book? List it free.
Your cover, blurb and store links, a first chapter readers can try, and numbers on where they stop. Host your advance copies free too.