VALIDATE EPUB
epubio validates the EPUB created in your book project with EPUBCheck. Technical findings are prioritised and linked to the relevant part of the workspace.
EPUBCheck verifies whether the package and files follow technical EPUB rules. It is an important basis for store delivery, but it does not replace editorial proofreading or the final review performed by each retailer.
The check reviews package data, content documents, references and navigation in the generated EPUB. epubio separates blocking errors from findings that require an informed review.
Instead of showing only a technical code, epubio explains the reason and points to the relevant area, such as book details, cover, structure or design.
Changes to manuscript, metadata or cover can affect the output. Validation therefore belongs to the current ReleaseTwin state and runs again for a newly generated file.
The file meets the technical rules checked by EPUBCheck. It does not promise acceptance by every store or complete review of content, typography and accessibility.
epubio prevents and explains many technical issues and guides you to the correction. Changes that affect content or design remain your decision; ambiguous choices are not guessed automatically.
The guided validation workflow focuses on outputs created from your epubio book project. It is not a general repair service for arbitrary EPUB files from other software.
Create EPUB from a traceable book state and resolve findings directly in the project.
Create an EPUB project