EbooksLaunch service

EPUB Validation & Preflight

Find structural and packaging problems before a retailer, distributor, or reader does.

What this service does: We run validation, interpret the errors, correct production issues within scope, and check the file as a publication rather than treating a zero-error report as the whole job.

What is included

  • EPUBCheck validation
  • Package and manifest review
  • Navigation inspection
  • Broken-link and missing-resource checks
  • Metadata consistency review
  • Targeted reading-system preview where practical
  • Corrected file and issue summary

Best fit for

Authors with an existing EPUB, publishers receiving files from freelancers, or anyone facing upload errors or inconsistent rendering.

Pricing: See current package pricing or request a project review.

Questions authors ask

Is passing EPUBCheck enough?

No. EPUBCheck tests conformance, but a valid file can still have poor design, weak navigation, inaccessible content, or retailer-specific display problems.

Can you diagnose retailer upload errors?

Yes, when the problem is reproducible from the file or metadata. Platform account issues may require the account holder to work directly with the retailer.

Do you guarantee acceptance everywhere?

No. Stores control their own content and account policies. We can make the file technically ready and address known file-level issues.

Related guidance

What is EPUBCheck?

What the validator checks and what it does not.

KDP EPUB preparation

Preflight for Kindle publishing.

Kobo EPUB preparation

Practical Kobo readiness guidance.

Ready to make the file publication-ready?

Send the manuscript, cover, and publication details. We will identify the right production path before work begins.