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Check an EPUB package and links

EPUB2/3 subset: OCF, OPF version/metadata, manifest, spine, resource/link/anchor integrity and active/protected flags.

  • Runs in your browser
  • No upload
  • Check before download

Processed on this device; files are never uploaded. EPUB2/3 subset: OCF, OPF version/metadata, manifest, spine, resource/link/anchor integrity and active/protected flags. No EPUBCheck or full conformance claim; external links are reported and never opened. Content is never executed. Limits: 10 MiB ZIP, 20 MiB expanded, 300 entries, 5 MiB per entry, 100 pages, 16 MP per image, a 15-second worker and 10 MiB of output. UTF-8 XML up to 512 KiB per part, 40 levels and 20000 nodes; no DTD or XInclude. EPUB subset: 250 manifest items, 2000 links and 500 issues. No CSS escapes, responsive srcset or xml:base. Edits: 512 characters per title or author and 20 authors; only the primary title is edited and alternate titles are kept. The cover selects an existing image; other metadata and navigation stay. This is not a privacy cleaner.

How to use this tool

  1. Local file

    Open a local EPUB and run the package validation. Inspect the container and OPF metadata, the manifest, the spine and the internal links. The original archive is not repaired or overwritten.

  2. Preview

    If a manifest entry points to a missing chapter.xhtml, the package has a missing-resource finding. Restore that file or correct its path in the source EPUB, then run it again.

  3. Validation report

    Read the resource or path and the issue code for each issue, including unresolved anchors. Save the report, and check the corrected EPUB separately with EPUBCheck for broader conformance.

Static profile

What does this result mean?

A clean report for the supported subset is not EPUBCheck or full EPUB conformance. External links are listed without being opened, and the book’s content is never run.

How do I resolve rejected or missing input?

Check the filename case, the relative paths and the fragment IDs. An archive that is unsupported or protected can't be made valid by hiding its findings. Correct the source, or use another suitable validator.

What are the limits of this tool?

A limited local subset of EPUB2/3: ZIP ≤10 MiB, expanded ≤20 MiB, ≤300 entries and ≤500 issues. No coverage of CSS escapes, responsive srcset or xml:base.