E-book QC

Check the following to confirm the quality of an e-book.

General Checks


Use the ePub Validator tool in the Digital Hub.

EPubs can also be validated using the IDPF online validator or a locally installed version of EpubCheck.

Check for common validation errors such as: dead or incorrect links; images or files in the package but not declared in the manifest section of the OPF file—every ePub directory should contain only the files necessary for the ePub.

Use the CSS Lint online validator or another validation method to confirm that there are no errors.

Scribe default: Name the CSS to match the client code.

Device Review

Review in the following devices and apps: iBooks, the current version of Adobe Digital Editions (ADE), iPad/tablet, Kindle.

Table of Contents


Do a page-by-page review.

Are those styles defined correctly in the CSS?

Page Breaks

Irregular page breaks may be due to the automatic division of oversized files.

To ensure proper layout on an iPad, each section that should start on a new page should be in its own HTML file. Scribe’s default standard is to optimize all ePubs for the iPad.

For an ePub to meet the requirements for Apple’s iBooks Store, no individual HTML file can be larger than 300KB.



If not, identify which list classes are not displaying properly and locate them in the CSS to look for possible causes.


Examples: Border vs. no border; do columns have appropriate proportions?

Tables with more than four columns might not render well on reading devices and might be cut off. Search the HTML files for tags, if necessary, to locate all tables.



If found, the link should either be corrected or commented out.

See also: Kindle Previewer URL checks.

Print Page Numbers in Text

Avoid referencing print page numbers when possible. If they must remain, they should be linked to the corresponding internal print page ID.


Examples: “See [chapter, figure, map, etc.]”


Foreign Characters

Check for any instances of combining unicode.

Check for images replacing characters (e.g., images of Hebrew text).


Device Navigation Items (NCX/toc.xhtml)

Note: toc.xhtml supercedes NCX in Epub 3.

Image Checks


Unless otherwise specified, the cover image should be at least 1800 pixels on its largest side (and should never have any side smaller than 500 pixels).

The image dimensions should not be in the HTML.

A max-height percent should be specified in the CSS to constrain the default display size (this is currently in the default CSS).

Does the text in the cover image match the text used in the interior?


If figure images are larger than 600 pixels in either dimension, a max-height or max-width percent should be specified (inline or in the CSS) to constrain the default display size.

Color Format


Metadata Checks

ACE Checker

Use the Ace by DAISY app to reveal any accessibility errors.

A link to Ace is also available in the Digital Hub.

Digital Hub Project Information

All available information should be present in the Hub record‘s Project Information tab.

This includes the following: Title, Publisher, BISAC Subject Codes, Print and E-book ISBNs, Creators and Contributors, Accessibility Options, and Extended Metadata (Additional Descriptive Data and Additional Titles).

Check that the text used (especially for titles) matches between the cover, the interior, and the metadata.

Navigation File Entries

They should usually be “Cover,” “Title Page,” and “Copyright Page.”

Small caps/italics do not work in toc.xhtml or ncx.

Consider adding punctuation.

Note: Small caps are not universally supported in toc.xhtml files (device side navigation). Using title case is the recommended approach to work around this issue.

File-As Name

Accessibility Metadata

Scribe recommends adding basic accessibility metadata to every ePub. That is available within the extended metadata section in Digital Hub records.

A typical, basic set of accessibility metadata would look like this:

<meta property="schema:accessMode">textual</meta>

<meta property="schema:accessMode">visual</meta>

<meta property="schema:accessModeSufficient">textual,visual</meta>

<meta property="schema:accessibilityFeature">tableOfContents</meta>

<meta property="schema:accessibilityFeature">readingOrder</meta>

<meta property="schema:accessibilityFeature">printPageNumbers</meta>

<meta property="schema:accessibilityFeature">index</meta>

<meta property="schema:accessibilityFeature">structuralNavigation</meta>

<meta property="schema:accessibilityFeature">displayTransformability</meta>

<meta property="schema:accessibilityHazard">none</meta>

<meta property="schema:accessibilitySummary">This publication conforms to the EPUB Accessibility specification at WCAG Level A.</meta>

Note: The accessibility feature "captions" refers to text content associated with embedded audio/video, not traditional figure captions that use {~scml:figh} and {~scml:figcap} styles in ScML.

The print ISBN is essential for accessibility and establishing the relationship between the print pagination and ePub page IDs.


Scribe’s standard is to keep the print ISBN live and to add the e-ISBN to CIP page.

Other Metadata

ePub 3 Checks

Page List


It should contain at least “cover,” “toc” (table of contents), and “bodymatter” (to indicate where the main content begins).

Kindle (.mobi) Checks

Though Amazon requires .epub to be delivered and not .mobi, build a .mobi file using Kindle Previewer to confirm that there are no conversion issues. There should be no errors or warnings during the build process (other than warnings about embedded fonts, which can usually be ignored).

Cover and TOC Buttons

Build errors (e.g., if the cover is not correctly identified) can result in a grayed-out button in the previewer.

Example: <a href=""\>Text <a href=""\>note</a\></a\>)

These will show as errors when building a .mobi file and will result in nonfunctioning links.


This is necessary for proper display in a Kindle viewer.


Do a page-by-page review.

URLs (Kindle Previewer Report)

If a link is reported due to an error, fix it.

Note: Scribe recommends adding a disclaimer to all books (both print and digital) to indicate that links were active at the time of writing.

Sample disclaimer: References to internet websites (URLs) were accurate at the time of writing. Neither the author nor [press name] is responsible for URLs that may have expired or changed since the manuscript was prepared.

Final Check

The .scml file is the archival file for the project, so it must match the content of the e-book.