Fixing KDP Ebook Validation Warnings: CSS and Font Limits
Resolve upload delays. Learn how to troubleshoot KDP validation warnings about font sizes, metadata files, and CSS formatting.
Eleanor Vance
Head of Digital Production
"Amazon KDP validates all uploaded EPUB files before catalog placement. Minor issues in CSS style sheets or metadata schemas trigger warning alerts that can delay book launches."
Core Key Takeaways
- Resolving Incompatible CSS Styling Limits
- Embedding Safe and Compliant Font Files
- Troubleshooting Missing NCX Navigation Metadata
This article is part of our comprehensive guide to Amazon KDP publishing.
1. Resolving Incompatible CSS Styling Limits
KDP supports specific CSS selectors. Advanced layouts (like absolute positioning or floating margins) fail validation checks and distort text.
- Remove absolute layouts and use relative margins.
- Keep CSS files clean and avoid inline style overrides.
- Validate files using EPUBCheck tools before KDP uploads.
2. Embedding Safe and Compliant Font Files
Ensure any custom fonts embedded in your EPUB include proper licensing. Mismatched licensing keys trigger automated rejections.
Master Amazon KDP Without Technical or Policy Pitfalls
From international Author Central setup and category mapping to AI policy compliance and paperback/hardcover manufacturing, let our publishing team handle your launch.
3. Troubleshooting Missing NCX Navigation Metadata
E-readers read NCX navigation files to build dynamic tables of contents. Check that your file maps every chapter heading cleanly.
The Takeaway
Validating ebook files ensures a fast launch. Golden Ivory Publishing validates all digital exports using standard EPUBCheck tools.
Master Amazon KDP Without Technical or Policy Pitfalls
From international Author Central setup and category mapping to AI policy compliance and paperback/hardcover manufacturing, let our publishing team handle your launch.
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