A Rundown on Accessible (Alternate) Formats

I started drafting something similar to this post for our website and decided to make it a blog post first. People ask me all the time about accessible formats (aka alternate formats) and the differences between the various types.

Introduction: The What, Why, and How

What is an Accessible Format?

An accessible, or alternate, format is simply a book (or other written material) converted into a format that a person with a print, or perceptual, disability can read.

What format a person needs varies by individual based on their abilities, which is not necessarily based on their disability. For example, a blind person might need Braille, but someone who is recently blind, might need audio because they haven’t learnt Braille yet.

Definition of Print Disability

In Canada, a perceptual disability (or print disability) is defined as:

a disability that prevents or inhibits a person from reading or hearing a literary, musical, dramatic or artistic work in its original format. (Copyright Act of Canada, Section 2)

Examples include visual, physical (e.g. not being able to hold a book), and learning impairments (which includes dyslexia and other reading disabilities).

How Do You Determine if Someone is Print-Disabled?

The question to ask is:

can someone “read” the book simply by changing the format? If yes, they have a print disability.

There is one major exception, which is illiteracy, because that’s a matter of education. However, in Canada and the United States, illiteracy is uncommon (less than 5%) and likely associated with a learning disability.

To weed out anyone who may simply prefer other formats and those who are not print-disabled, organizations may require documentation. Each organization will have different policies as to what they require in order to qualify for the services meant for print-disabled. It varies a lot: anything from a self-declaration form to a full evaluation (which can cost thousands and take days to do).

Why are Accessible Formats Necessary?

Most print books are not available in a format that a print disabled can “read” (the World Blind Union estimates a “few per cent”), so many organizations (both for profit and non-profit) convert books in an accessible format.

The purpose of conversion is to break the barrier between the reader and the book.

How do you Create Accessible Formats?

The overall process is to go from print -> ebook or electronic text -> audio.

Where you start and stop in this process depends on what you can source (either through purchasing or asking the publisher), and what format the individual needs.

I won’t go into detail here, because there are lots of different formats to consider and there are different ways to create them. I hope to write a series of posts this year that will cover this one topic in more detail.

E-Book Formats

Ebooks come in all sorts of formats and can vary in its level of accessibility, so let’s break it down even further.


Pro: Looks exactly like the original book (including images and pagination).

Cons: Cannot adjust text size (only zoom). Reflow of text not always an available feature and even when it is, it does not always work well. Typically difficult to read on small screens.

PDF works well for sighted people, particularly for books where the page numbering is important (for whatever reason).

PDFs can also vary greatly in accessibility. Minimally, the PDF needs to be text readable (so that text to speech will work), but should have a few more pieces. Check out my blog post on PDF accessibility for details on how to test whether a PDF is text readable and a list of other features that makes PDF files more accessible.

Electronic Text (E-text) & ebook

Pros: Text will reflow, with images. Works well on any size screen. Easy to adjust text size.

Cons: Can have pagination, but in most formats, page numbering may or may not reflect original. Layout not like original print book.

I lumped e-text and ebook together, because in terms of accessibility, they’re very similar. The biggest difference is the file format and what programs are compatible. Much like PDF, accessibility can differ depending on how much is formatted and linked.

Formats vary from one organization to another, but this is how I typically see it broken down:

  • ebook: EPUB2, EPUB3, MOBI, LIT
  • e-text: doc/x, RTF, HTML

My understanding is that EPUB (particularly 3) has some extra features, such as being able to embed video, but accessibility-wise, I haven’t heard big differences (except in regards to DAISY, which I’ll touch on below).

E-text and ebook work particularly well for text-to-speech, for example because the flow of the text is not broken up by line or page breaks, and image captions (or alt text) being read in the middle of a paragraph.

E-text in RTF is the most interoperable, meaning that it works for the most number of programs and devices, including refreshable Braille.

A Note on Large Print

In print, it made sense that you need a large print version, but in the digital world, that doesn’t usually make sense. A PDF, ebook, or e-text file will allow a user to enlarge the text (and images) in one way or another.

I am not saying we don’t need large print anymore (as I have encountered cases where it is necessary), but if someone is asking for a digital file, I would be instead asking about what device and application they will be using to read it.

A Note on Braille

As I mentioned, RTF works for refreshable Braille.

The only other form of Braille I know of is printed (paper) Braille. In these cases, RTF (and other document formats) can be opened in the Brailler software in order to print a Braille version.

Most organizations that I know of will only print Braille if absolutely necessary, preferring to loan copies from other organizations if possible due to the large amount of storage space needed.


There are a couple of different audio formats as well, so we’re breaking this one down as well.

A Note on Text-to-Speech

Before we get into audio formats, a quick note that many people who need material in an audio format frequently use accessible text-based formats with text-to-speech software.

These days it’s built into commonly used operation systems (OS X, Windows 7+, some flavours of Linux, iOS, Android, etc.), not to mention all the specialized software and apps available.

The main advantage of text-to-speech is that the user can choose among the voices available, pitch, and speed.

While for fiction and popular non-fiction many people prefer live narration (real people reading), synthesized voices tend to stay understandable even at faster speeds, which is useful for skimming, or reviewing.

Text formats (and DAISY with text, which I cover below) also allow full text searching.


DAISY is a specialized audio format that basically allows increased navigation and other features.

DAISY also has a couple of different formats: DAISY 2.02, DAISY 3.

While DAISY 3 has improvements, numerous software and hardware playback devices are incompatible. Some of the free or cheaper DAISY creation software do not fully support DAISY 3 either. EPUB3 is also frequently being used as a text only substitute, but again, compatibility varies with playback devices.

DAISY can be:

  • text only, in which case the player will use text-to-speech capabilities,
  • audio only, in which case navigation is typically limited (e.g. no full text search), or
  • both, in which case, some players will ignore the pre-made audio in favour of text-to-speech.


Most audiobooks that you buy will come in MP3 format, and otherwise, can easily be converted to MP3. Audio files within a DAISY are usually in MP3 format as well.

The main disadvantage is the lack of all the additional features (particularly around navigation) that DAISY allows. To make it a little easier, MP3 files are usually divided by chapter or section, or some organizations do it by page (but this makes for a really long playlist).

The main advantage of MP3 is its interoperability. I can’t think of a single device that supports audio, but doesn’t support MP3 without specialized software.

Due to its popularity, people commonly also know how to manage MP3 files, as opposed to DAISY, which many people will not have heard of (let alone know how to use).

A Note on CD

Both DAISY and MP3 can be burned onto CD.

While DAISY CDs need specialized players, most modern CD players can play MP3.

Of course, many audiobooks still come in Audio CD format, but that usually means 5 times the number of CDs, which can be difficult for visually impaired readers.

Concluding Note

Sometimes the format required is very particular to a person, so whether a format is accessible, depends on who is “reading” it.

There was a lot to cover, so if I missed something, please let me know.

Author: Cynthia

Technologist, Librarian, Metadata and Technical Services expert, Educator, Mentor, Web Developer, UXer, Accessibility Advocate, Documentarian

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