Most EPUB ingestion problems start with navigation drift. This checklist helps you keep chapter order, TOC links, and reading flow stable across export, validation, and device checks.
Use consistent heading levels for chapter titles and major section breaks.
Avoid manual visual-only headings that look right but are not structural markers.
A clean heading hierarchy is the foundation for reliable EPUB navigation files.
Open the EPUB and click every TOC entry in order from first to last chapter.
Verify links jump to the correct heading and not to prior or duplicate anchors.
Include front and back matter entries only when they are intentionally part of reader navigation.
Run EPUB validation after every structural edit that changes headings or section order.
Treat missing-nav, duplicate-anchor, and broken-link warnings as release blockers.
Fix source manuscript structure and export again instead of patching EPUB internals manually.
Spot-check the same file in at least two reading environments before upload.
Confirm navigation opens quickly, chapter starts look correct, and back matter links resolve.
Save one validated release EPUB and upload that exact file to your distributor.
| Checkpoint | Pass signal | Common failure |
|---|---|---|
| TOC click-through | Every entry opens expected chapter start | Entries jump to wrong heading or duplicate anchor. |
| Front/back matter links | Only intentional sections appear in navigation | Empty or placeholder sections show up in TOC. |
| Chapter sequencing | Reader advances in expected order | One chapter appears out of order after export. |
| Multi-reader check | Same navigation flow in two readers | One reader shows missing or broken navigation links. |
Fix: Rebuild export from a manuscript with recognized heading structure.
Verify: Validator confirms navigation document is present.
Fix: Normalize duplicate headings or malformed anchor targets in source.
Verify: Each TOC entry jumps to the intended chapter heading.
Fix: Ensure each chapter/section heading produces a unique target.
Verify: Validation no longer reports duplicate identifiers.
Fix: Correct link targets and remove stale references before re-export.
Verify: All navigation and internal links resolve without errors.
Fix: Review manuscript section ordering and regenerate EPUB from the corrected sequence.
Verify: Reader next/previous flow matches intended order.
Fix: Confirm distributor/validator is using the newest exported file.
Verify: Renamed latest EPUB returns clean navigation checks.
Use the same workflow in one workspace: draft, export, run checks, fix source, and publish one clean release-candidate file.
Visual TOC rendering can hide structural issues like duplicate anchors or missing nav metadata that validators still detect.
Only as a last resort. Source-first fixes are safer and prevent the same issue from returning on later exports.
After any change to chapter order, heading text, or front/back matter sections.