Test your ebook for errors before you upload to Amazon KDP, Apple Books or Kobo. We check structure, required files, table of contents, images, links and metadata — instantly, and privately in your browser.
or click to choose a file — your book never leaves your device
Choose EPUB File🔒 100% private — your file is checked in your browser and never uploaded to any server.
A single structural error can get your ebook rejected by Amazon KDP, Apple Books or Kobo — or worse, accepted but displayed badly on readers' devices, hurting your reviews. This free EPUB checker catches the most common problems authors miss before they cost you a launch.
We validate the core structure of your EPUB file: the required mimetype and container.xml files, the OPF package and manifest, your spine reading order, the navigation document (table of contents), embedded images and fonts, internal links, and your metadata (title, author, language and identifier). These are the elements retailers check when you upload.
The official EPUBCheck is a Java tool that runs deep schema validation. This browser-based checker focuses on the practical, high-impact issues that actually cause rejections and display problems — fast, free, and private. For a guaranteed retailer-ready file, our team uses full professional validation as part of every EPUB conversion.
It validates your ebook's internal structure — required files, table of contents, images, metadata and links — so your book is accepted by retailers and displays correctly for readers.
Yes — completely free, no signup. Your EPUB is checked privately in your browser and never uploaded anywhere.
This tool finds and explains the issues. If you'd like them fixed, our EPUB conversion service delivers a clean, validated, retailer-ready file.
Completely. The check runs entirely in your browser. Your file is never uploaded, stored, or seen by anyone.