Make Accessible Ebooks

2018-03-01 by Sean Harrison

I have been producing ebooks of all shapes and sizes since 1999, but until mid-2017 I hadn’t spent a lot of time thinking about accessibility. I knew it was important to create ebooks that could be used by all people. I just didn’t realize how important it is.

My experience is not uncommon: Ever since the ebook revolution really got under way in 2007, publishers have been producing ebooks with widely varying accessibility, and most readers have been putting up with it (although readers who need accessibility have been frustrated). Some examples:

  • Many early ebooks used images in place of text that included non-ASCII characters. These images-as-text would disrupt the reading process for those using screen reading software (not to mention looking hideous to those who were seeing them).

  • Early ebooks routinely converted tables to images, making the information in the tables completely unavailable to people who could not see them.

  • Publishers have been sloppy at best about including alt-text (textual descriptions of visual content) with figures, tables, mathematics, and other visually dense sources of information.

A change in the tide occurred in 2017: The public began to demand that digital content be accessible. For example, in March 2017 U.C. Berkeley was forced by U.S. Justice Dept. order to take down much of its free course materials because these materials were not accessible. Scans of print pages cannot be understood by sight-impaired users, and lecture videos without captions cannot be understood by hearing-impaired users.

Inside Higher Ed: Berkeley Will Delete Online Content

Starting March 15, the university will begin removing more than 20,000 video and audio lectures from public view as a result of a Justice Department accessibility order. By Carl Straumsheim // March 6, 2017

In 2017, the publishing industry also began to respond seriously to the public’s demands. Two significant responses created bookends around 2017:

  1. In January 2017 IDPF released the new EPUB 3.1 specification, which headlines accessibility as its most important change.1

  2. In January 2018 DAISY released v. 1.0.0 of Ace, its new EPUB accessibility auditing tool.2

I also was becoming more attenuated to the need for digital content to be accessible. In mid-2017 I was invited to give an industry workshop on the subject of ebook accessibility. It is often the opportunities to teach that provide the greatest learning experiences. By this point, I was eager to incorporate accessibility into my company’s ebook production workflow, so I gladly accepted the opportunity to learn and to teach “Making Ebooks Accessible and Discoverable” at ECPA PubU in November 2017.

As I studied the issue of digital content accessibility, my awareness grew into enthusiasm: Making content accessible provides a great opportunity for publishers to reach a wider audience. It is also the right thing to do to, to “do good and to share with others” and to “carry each other’s burdens.”3 When publishers make their digital content fully accessible, they are providing greater opportunities to people who have traditionally been excluded from access. But this does not have to be an act of pure altruism: It just makes business sense, and more and more so all the time.

The Business Case for Making Accessible Ebooks

An accessible ebook is more valuable to the publisher than a non-accessible ebook, for several reasons.

1. An accessible ebook can be used by a larger number of users, in a wider variety of contexts. For example, in addition to those who need audio input due to limited sight, more and more people are “reading” books in audio-only contexts (such as while driving). An accessible ebook with well-crafted alt-text will be more completely understandable to those who are using it in such an audio-only context.

2. Publishers who don’t make their ebooks accessible risk having their products excluded from the marketplace. As the public’s demand for accessibility increases, there is a real risk that major retailers will respond to this demand by insisting that ebooks on their platforms be accessible, either by hard exclusion (removal from the platform) or soft (exclusion from product search results). These changes often happen with little or no warning. Publishers need to prepare for this probability by ensuring that all of their ebooks meet at least minimum accessibility standards.

3. An accessible ebook is more discoverable in product searches. It is unclear how much of the content of ebooks are being used by retailers to respond to user searches: Some platforms (e.g., Google Books) use content search more than others. But any retailer who is not using content search now will experience competitive pressure to do so, using all of the data at their disposal to provide more and more precise product recommendations to their customers. An accessible ebook is one in which all of the content can be ingested into the search engine, making the ebook more discoverable in customer product searches. When figures, tables, and embedded videos are accompanied by descriptive captions and alt-text and structural semantics, this content can be used to deliver a more compelling buying experience to customers.

Getting Started Making Accessible Ebooks

For those who are just getting started on the ebook accessibility journey, as I was in 2017, the following resources are an excellent starting place.

Ace, by DAISY

2018 January 29 (version 1.0.0). Ace, the Accessibility Checker for EPUB.

DAISY is the content accessibility organization (“Making Information Accessible to All”).4 In January 2018 they released v. 1.0.0 of Ace, a command line tool for auditing an EPUB for accessibility compliance. Ace 1.0.0 implements the requirements and recommendations of EPUB Accessibility 1.0 (below). Ace is also open source (free), and it is straightforward to install and use.

I read somewhere that the first step in making a change is to measure the thing you want to change. There is at present no easier way to start measuring ebook accessibility than to install Ace, put your ebooks through its paces, and start implementing the changes it suggests.

EPUB Accessibility 1.0

2017 January 5. Conformance and Discovery Requirements for EPUB Publications.

IDPF (which is now part of W3) builds on the content and structure of WCAG 2.0 (below) to provide an introduction to accessibility in the EPUB context. While many of the requirements and recommendations are not (yet!) being used by reading systems or retailers, (a) they will be soon, and (b) meeting these requirements helps to ensure that a publisher’s ebooks are future-proof.

Web Content Accessibility Guidelines (WCAG) 2.0

2008 December 11.

These W3 guidelines for web content accessibility are not ebook-specific, but they are applicable to ebooks and provide the basis for discussion. Although WCAG is formatted like a specification, it is written more as an introduction, to be approachable for those who are just getting started. I cannot recommend highly enough that everyone who is involved with producing digital content should read and internalize these guidelines.


In late 2017 Book Genesis began producing ebooks that meet basic accessibility standards. I have learned, in the months since then, that accessibility (like network security) is more of a journey than a final destination: You can always do more and go further. Start by meeting the most basic level of the EPUB Accessibility 1.0 standards, and then make improvements from there. And feel free to get in touch with anything you would like to discuss further.

Specifications and Resources

The following specifications, guidelines, and resources are given in chronological order from the date of publication or revision.

Web Content Accessibility Guidelines (WCAG) 2.0

2008 December 11.

HTML5: A vocabulary and associated APIs for HTML and XHTML

2014 October 28.

EPUB Structural Semantics to ARIA Roles Mapping Guide

2016 August 1.

Techniques for WCAG 2.0

2016 October 7.

EPUB 3.1

2017 January 5.

EPUB 3.1 Changes from EPUB 3.0.1

2017 January 5.

EPUB Accessibility 1.0

2017 January 5. Conformance and Discovery Requirements for EPUB Publications.

EPUB Accessibility Techniques 1.0

2017 January 5.

EPUB 3 Structural Semantics Vocabulary

2016 January 5.

How to Meet WCAG 2.0

2017 July 20 (version 2.5). A customizable quick reference to Web Content Accessibility Guidelines (WCAG) 2.0 requirements (success criteria) and techniques.

Accessible Rich Internet Applications (WAI-ARIA) 1.1

2017 November 02. W3C Proposed Recommendation.

Digital Publishing WAI-ARIA Module 1.0

2017 November 02. W3C Proposed Recommendation.

Ace, by DAISY

2018 January 29 (version 1.0.0). Ace, the Accessibility Checker for EPUB.

1 EPUB 3.1:

2 DAISY Ace:

3 Heb. 13:16; Gal. 6:2.

4 The DAISY Consortium:

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