EPUB FixerKDP upload error scanner

EPUB error guide

EPUB check before Kindle upload

Check the exported EPUB you plan to send through Kindle Previewer or KDP, including TOC, links, cover wiring, OPF, NCX, manifest, and ZIP package problems.

Best fit

You are preparing the Kindle manuscript file.

Upload the reflowable .epub that will go into the Kindle or KDP workflow.

Report shows

What Kindle tools may reject.

The scan checks package wiring, navigation, NCX, OPF metadata, links, anchors, cover-image wiring, manifest entries, and ZIP rules.

Stop when

The problem is Kindle account or book setup.

KDP bookshelf, categories, pricing, DRM choice, review status, and marketing-cover upload are not EPUB structure checks.

Scan EPUB structureSee an example report

Scan when the message does not name the affected path. The report shows affected paths and repair decisions, not manuscript text.

No signup before the scan report.Checks EPUB package paths, not manuscript text.Repair download only after EPUBCheck passes again.

Need fixed-layout, DRM, or source-file help? Check unsupported or review-first EPUB cases.

Match these report titles

  • EPUB check before Kindle upload
  • EPUB check before KDP upload
  • Kindle upload EPUB structure check
  • Check EPUB before Kindle Previewer
  • Kindle Previewer preflight EPUB check
  • EPUB TOC, OPF, NCX, link, cover, manifest, or ZIP issue before upload

Use this guide when

Your message matches "EPUB check before Kindle upload" or one of the report titles above.

Upload if

You have the exported reflowable .epub and need the affected path, file, field, or repair decision before editing.

Handle outside this tool

Use the source tool or publishing workflow for DOCX, PDF, KPF, KCB, fixed-layout, comics, image-first books, DRM, visual design, or KDP listing and approval problems.

Read the scan report

Decide if this report item matches.

Use the report label, affected file, and repair decision together. A matching title alone is not enough if the file path or EPUB structure points to a different problem.

Error textAffected pathDecisionRepair, review, or stop

A useful report does not stop at the error name. It connects the message to an internal file and a next action.

Match the report title.

Look for "EPUB check before Kindle upload" or the closest title above. Keep the original EPUBCheck, KDP, or Kindle Previewer wording if it differs.

Check the affected file first.

Use the Affected area, Source file, Target file, or Problem type rows before editing OPF, nav, XHTML, CSS, or image paths.

Follow the repair decision.

Repairable means one clear structural change. Needs review or Not supported means use the named file, source project, or platform step.

Keep with your repair note.

Copy these fields from the report instead of rebuilding the fix from memory.

Source file
Target path or field
Original error
Repair decision
Next step

1. Example report output

What a Kindle upload preflight report should show.

A useful report should map the upload risk to one EPUB package area.

Kindle-facing file

The final .epub manuscript file, not the DOCX, PDF, KPF, or KCB source.

Navigation layer

nav.xhtml, toc.ncx, OPF manifest, and spine wiring for Kindle table of contents behavior.

Reference layer

Chapter XHTML, CSS, images, anchors, and internal links that Kindle Previewer may validate strictly.

Package layer

content.opf, manifest entries, media types, cover-image property, container.xml, and ZIP wrapper.

Decision

Retry-ready, checked repair, manual review, or outside EPUB Fixer scope.

The report should tell you where to look before you open Kindle Previewer again.

2. Next step

Choose the next Kindle upload step.

The scan result should decide whether you retry, repair, or return to the source export.

Retry upload

The scan does not find a supported blocker.

Use Kindle Previewer and KDP's upload screen as the final checks for the platform workflow.

Repair package

The report finds one clear wiring problem.

Use checked repair when OPF, manifest, media type, navigation, cover property, path, or ZIP wrapper data can be aligned safely.

Fix source

The issue needs author or formatter judgment.

Use the source tool when the report points to missing content, no reliable TOC, ambiguous anchors, or layout-sensitive fixes.

3. Concrete path example

A Kindle upload check can expose an NCX or nav mismatch.

Kindle tools can care about navigation files even when the chapters open.

Before Kindle upload:
Previewer target file: final.epub

Report:
Navigation file: OEBPS/nav.xhtml
Legacy NCX: OEBPS/toc.ncx
OPF spine toc: points to old-toc
Decision: manual review if nav and NCX disagree; checked repair only when one intended navigation target is clear

Do not delete nav.xhtml or toc.ncx just because one looks older. Check how the OPF manifest and spine connect them first.

Quick decision

Decide whether the Kindle issue is in the EPUB file.

This check is for the EPUB manuscript file. Kindle account, KDP listing, DRM, pricing, review, and approval tasks stay outside it.

Good fit

The Kindle manuscript file is a reflowable EPUB.

The scanner can inspect the package parts that Kindle Previewer and EPUBCheck usually complain about.

Manual fit

The scan names a path but the fix affects reading order.

Use the report as a checklist, then decide the final TOC, spine, anchor, or missing-content fix in the source workflow.

Not this tool

The problem is not inside the EPUB package.

KDP account setup, listing metadata, cover upload, pricing, DRM, review status, and content policy need the Kindle or KDP workflow.

Start here

Check the Kindle upload file, not the source manuscript.

A Kindle upload problem often appears after export, inside the EPUB package. Upload the same EPUB that Kindle Previewer or KDP will inspect.

Matched

What it means

A Kindle upload uses the finished EPUB package. The visible book can look fine while OPF metadata, navigation, links, resources, cover wiring, or ZIP packaging still disagree.

Matched

Can it be fixed automatically?

A checked repair is possible when one package correction is clear and can be validated again, such as OPF manifest, navigation declaration, media type, cover-image property, path, anchor, or ZIP wrapper alignment.

Matched

What to check next

Use the same .epub file you would send to Kindle Previewer or KDP.

Matched

What not to assume

It does not manage Kindle account settings, create KPF files, choose DRM, approve listing metadata, fix pricing, judge content policy, redesign the book, or decide whether Kindle accepts the upload.

Common situations

Common EPUB checks before Kindle upload.

Start from the Kindle tool you are about to use.

Matched

You want to open Kindle Previewer with fewer surprises.

Previewer can surface TOC, navigation, conversion, missing resource, and package errors.

Scan the EPUB first and use the affected path as your Previewer checklist.

Matched

You are worried about the Kindle table of contents.

TOC failures often involve nav.xhtml, toc.ncx, OPF manifest, and spine wiring rather than visible chapter headings alone.

Check navigation wiring before rebuilding the book.

Matched

You want the internal EPUB cover to be recognized.

The Kindle manuscript cover depends on OPF cover metadata, manifest item, cover-image property, and the packaged image file.

Scan cover wiring; handle KDP marketing cover upload separately.

Kindle upload check phrases to check

EPUB check before Kindle upload: scan OPF, nav.xhtml, toc.ncx, links, anchors, cover wiring, manifest, media type, container.xml, and ZIP package structure before Kindle Previewer or KDP upload.

Where Kindle upload checks usually fail

An author, formatter, or small publisher is preparing a Kindle or KDP upload and wants to check the exported EPUB before Kindle Previewer or KDP rejects it.

What it means

Kindle upload checks can fail on invisible package wiring.

A Kindle upload uses the finished EPUB package. The visible book can look fine while OPF metadata, navigation, links, resources, cover wiring, or ZIP packaging still disagree.

Common causes include disconnected nav.xhtml or toc.ncx, stale OPF spine references, missing resources, missing anchors, wrong media types, cover metadata mismatches, missing manifest entries, container.xml path mistakes, and bad ZIP packaging.

Before you edit

Check Kindle-facing paths before re-exporting.

When the EPUB is already exported, the fastest useful check is usually OPF, nav.xhtml, toc.ncx, links, anchors, images, manifest entries, cover wiring, and ZIP packaging.

  1. 1Use the same .epub file you would send to Kindle Previewer or KDP.
  2. 2If you already have a Previewer message, paste that line after selecting the file.
  3. 3Check the report for OPF, nav.xhtml, toc.ncx, XHTML, CSS, image, anchor, manifest, cover, media-type, container, or ZIP findings.
  4. 4Use checked repair only when the report shows one clear package change and EPUBCheck passes again.
  5. 5Use the source tool when the report depends on reading order, missing assets, visual layout, or author intent.
  6. 6Handle Kindle or KDP account, listing, pricing, DRM, review, and approval issues outside this scan.

Why Kindle tools check it

Why Kindle upload tools inspect EPUB package files.

KDP eBook file formats

KDP supports EPUB files that meet Kindle Publishing Guidelines and recommends checking the file with Kindle Previewer before upload.

EPUBCheck

EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.

EPUB 3.3 package rules

The OPF file is the EPUB's map: metadata, file list, reading order, and navigation wiring. KDP and EPUBCheck use it to decide whether the book package is coherent.

Can this be fixed safely?

When a Kindle upload issue can be repaired here.

When automatic repair is safe

A checked repair is possible when one package correction is clear and can be validated again, such as OPF manifest, navigation declaration, media type, cover-image property, path, anchor, or ZIP wrapper alignment.

When you need manual review

It does not manage Kindle account settings, create KPF files, choose DRM, approve listing metadata, fix pricing, judge content policy, redesign the book, or decide whether Kindle accepts the upload.

Before / after example

Before: the OPF spine points to an old NCX id or the manifest misses the navigation property. After: align the wiring only when the intended navigation file is clear and EPUBCheck passes again.

Ready to retry?

Upload the EPUB for a Kindle upload preflight.

Upload the file you would send through Kindle Previewer or KDP. The report tells you whether the issue is a checked package repair, a source-tool change, unsupported here, or a Kindle/KDP task outside this scanner.

Upload EPUB to scan

FAQ

Questions authors ask before Kindle upload.

What should I check before Kindle upload?

Check the final EPUB package: OPF metadata, manifest, spine, nav.xhtml, toc.ncx, links, anchors, images, cover wiring, container.xml, and ZIP packaging. EPUB Fixer reports affected paths and a next-step decision.

Is Kindle upload the same as KDP upload?

For this page, Kindle upload means the EPUB manuscript file going through Kindle Previewer or KDP. Account, listing, pricing, and review workflow are separate from the EPUB structure check.

Can this fix Kindle Previewer conversion failed?

Only when Previewer fails because of a supported EPUB structure issue. KPF creation, visual layout, complex conversion, fixed-layout books, and source formatting still belong in the Kindle or source workflow.

Can I use this with KPF or Kindle Create project files?

No. Upload a real .epub file here. KPF, KCB, DOCX, PDF, and source projects are outside this scanner.

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