Blog

Apple Books EPUB Requirements Explained for Self-Publishers

Apple Books EPUB Requirements: A Practical Guide for Self-Publishers

Estimated reading time: 18 minutes

  • Apple Books requires EPUB 3-compatible files that pass EPUBCheck and include correct metadata and an embedded cover.
  • Maintain correct package structure (mimetype, META-INF/container.xml, OPF manifest) and optimize images, fonts, and file size.
  • Use validated tools to convert and preview files on Apple devices to reduce rejections and speed publishing.

Table of Contents

What Apple Books expects

Apple’s storefront enforces consistent quality across devices. Files described as meeting apple books epub requirements must follow EPUB 3 rules, validate with EPUBCheck, and include a correct embedded cover and metadata.

A valid EPUB has three core parts: an uncompressed mimetype file at the root, a META-INF folder with container.xml, and a content folder (commonly OEBPS) holding XHTML, CSS, images, fonts, and the Navigation Document.

Use tools that generate modern EPUB markup to avoid legacy artifacts like NCX; for authors converting from Word or Pages, consider a converter that enforces these package rules. For example, an article on Epub Converter For Kindle shows common conversion pitfalls and fixes.

Preparing files that won’t be rejected

1) File format: EPUB 3 is the standard

Target EPUB 3.3-compatible output where possible. EPUB 3 replaces NCX with the Navigation Document and improves accessibility features.

If your export tool only produces EPUB 2, upgrade or convert the package before upload to save manual fixes later.

2) Correct package structure

The root must contain an uncompressed mimetype file with the exact string “application/epub+zip”, a META-INF folder with container.xml, and a package document (OPF) referenced correctly.

Include manifest entries for every resource (HTML, CSS, images, fonts). Missing manifest items are a common validation failure.

3) Metadata: match cover and catalogue fields

Ensure title, author, language, and identifiers (ISBN or unique ID) are accurate and consistent with your storefront listing.

Apple flags mismatches; make embedded metadata match what you plan to enter in the partner portal.

4) Cover requirements and thumbnail readiness

Embed a front cover image inside the EPUB and reference it in the manifest. The internal cover should match the storefront art you upload.

Avoid extremely large images and save artwork optimized for thumbnail readability. If you use a specialist cover tool, it can ensure title legibility at small sizes.

5) Images, fonts, and multimedia

Optimize images for reasonable pixel dimensions and compression. Use JPEG or PNG with correct MIME types.

Embed fonts only when the license permits, and register them in the manifest and CSS with @font-face.

Multimedia is allowed in EPUB 3 but requires proper HTML5 tags, fallbacks, and MIME types; always test playback on Apple devices.

6) Reflowable vs fixed layout

Choose reflowable EPUB for most non-fiction for better accessibility and compatibility. Use fixed layout only when exact page placement is essential, such as in picture books or comics.

7) File size and packaging

Keep packages reasonable in size — industry guidance suggests staying well under 1 GB. Large assets increase processing time and can cause issues.

If you need many images or media files, consider separate enhanced editions or lower-resolution assets for the ebook.

8) Accessibility and reading systems

Use semantic HTML (headings, paragraphs, lists) and ARIA roles when needed. Ensure a logical reading order and use the EPUB Navigation Document for EPUB 3.

9) Tools and workflows that reduce errors

If you’re not comfortable editing EPUB internals, use a tool that produces store-ready EPUBs and validates the package.

Many authors rely on dedicated platforms that handle conversion and cover production in one place; one such provider — Bookautoai — combines manuscript formatting, EPUB conversion, and cover generation to reduce mismatches between assets and metadata.

Testing, validation, and submission tips

1) Validate with EPUBCheck

Run EPUBCheck before upload and resolve fatal errors. Apple expects strict compliance and treats fatal validation errors seriously.

2) Check the navigation and reading order

Open the EPUB in multiple readers — include Apple Books on macOS/iOS — and verify the table of contents, page order, and internal links.

3) Confirm cover and metadata alignment

Preview the embedded cover and confirm it matches the external storefront art in title, author, and composition.

4) Test assets on target devices

Test images, fonts, and any multimedia on Apple Books to confirm rendering and fallbacks.

5) Avoid common rejection triggers

Watch for missing or malformed mimetype files, incorrect container.xml entries, absent Navigation Documents, and missing manifest items.

6) Submission checklist

Pass EPUBCheck without fatal errors, embed and match the storefront cover, confirm metadata matches partner portal inputs, and verify reading order and links.

7) Use the right tools for conversion and cover design

Manual fixes are possible but time-consuming. For frequent publishing, a reliable conversion tool reduces friction and rework.

If you handle both manuscript and artwork, consolidating those steps reduces metadata mismatches and upload errors.

Practical examples and troubleshooting

Problem: EPUBCheck fails with “no package document.”

Fix by inspecting META-INF/container.xml to ensure it points to the correct OPF path and filename.

Problem: Embedded images look blurred on Apple Books.

Fix by checking image resolution and compression; use 72–150 DPI for images in reflowable EPUBs and avoid excessive downscaling.

Problem: Internal links or the table of contents don’t work.

Ensure all XHTML files are listed in the manifest and the Navigation Document references correct targets and anchors.

Problem: Fonts don’t display as expected on iPhone.

Verify font files are included in the manifest, referenced with @font-face in CSS, and have permissive embedding licenses.

Problem: Apple rejects an EPUB for “invalid package metadata.”

Confirm required metadata fields (title, language, identifier) are present and that language tags follow BCP-47 (for example, en-US).

When to ask for help and when to automate

If you publish rarely, learning basic EPUB internals helps you troubleshoot issues. If you publish regularly, a proven conversion tool saves time and reduces rework.

For many authors, consolidating manuscript formatting, EPUB conversion, and cover generation in one place reduces the number of manual steps and common errors.

Final thoughts

Meeting apple books epub requirements is about discipline: consistent metadata, correct package structure, optimized assets, and thorough validation.

Invest in reliable conversion and asset tools so you spend less time fixing technical problems and more time writing and marketing your work.

FAQ

What format does Apple Books require?

Apple Books expects an EPUB package compatible with EPUB 3 standards; files must pass EPUBCheck and include correct package structure and metadata.

Will Apple Books accept EPUB files made with Word or Pages?

Pages can export EPUBs, but always validate the output with EPUBCheck and test on Apple Books; dedicated converters often produce cleaner results.

Do I need a special cover size for Apple Books?

Apple expects a clear, readable front cover embedded in the EPUB and a storefront cover upload. Optimize typography and contrast for thumbnails.

Should I use fixed layout for non-fiction?

Generally no — use reflowable EPUB for non-fiction for better accessibility and device compatibility.

How big can an EPUB be for Apple Books?

Keep files as small as practical; industry guidance suggests staying well under 1 GB and optimizing images and media.

How can I reduce validation errors?

Use a tool that creates valid EPUB 3 packages, check EPUBCheck output, verify metadata, and test on Apple Books devices to reduce common human errors.

Sources

Apple Books EPUB Requirements: A Practical Guide for Self-Publishers Estimated reading time: 18 minutes Apple Books requires EPUB 3-compatible files that pass EPUBCheck and include correct metadata and an embedded cover. Maintain correct package structure (mimetype, META-INF/container.xml, OPF manifest) and optimize images, fonts, and file size. Use validated tools to convert and preview files on…