Accessible EPUB

What changed, and whether it is about you

The European Accessibility Act, Directive (EU) 2019/882, adopted in 2019, has applied since 28 June 2025. Among the products and services it covers are e-books and the software used to read them.

There is an exemption, and it is a wide one. Micro-enterprises, meaning fewer than ten persons with an annual turnover or balance-sheet total not exceeding €2 million, are exempt from the obligations the Act places on service providers. The overwhelming majority of self-published authors are inside that definition.

So why does this matter? Because the exemption covers you and not the shop. Amazon, Kobo, Apple Books and every aggregator selling into the EU are covered. They have to be able to say what they are distributing, and the only thing they can read to find out is the metadata inside the file. The practical consequence is already visible: retailers surface accessibility information on product pages, and files that declare nothing are at the bottom of a list that is only going to get more consequential.

And underneath the compliance question there is the plain one. Roughly one reader in forty in Europe uses some form of assistive technology. A badly built EPUB is not a legal risk to most authors. It is a book some people cannot read.

The structure half

Most of accessibility in a text-only book is just a correctly built EPUB. If the file is good, it is largely accessible already:

• Reflowable text, not images of text. A scanned page is unreadable to a screen reader and cannot be enlarged. This is the single biggest failure, and it is almost always the result of exporting a PDF and converting it.
• Real headings. An h1 for the chapter title and h2/h3 beneath it, in order and without skipping a level. A screen-reader user navigates by heading the way a sighted reader navigates by flicking pages; a book whose “headings” are large bold paragraphs cannot be navigated at all.
• A logical reading order. The order of the markup is the order it is read aloud. Anything positioned visually rather than placed in the flow is read somewhere unexpected.
• Marked-up sections. epub:type and a matching DPUB-ARIA role on each section say what it is (a chapter, a copyright page, a glossary) rather than leaving a reading system to infer it.
• A navigation document and landmarks. The contents menu, and the declaration of where the body of the book starts.
• Alternative text on every image that carries meaning, and an empty alt attribute on every image that does not. Describing an ornament is worse than leaving it undescribed: a screen-reader user hears it at the top of every chapter.

The metadata half

This is the part almost nothing in the self-publishing toolchain produces, and it is the part a retailer reads. It lives in the EPUB’s package document, in the schema.org vocabulary:

The part that gets this wrong

Metadata is an assertion. A file that declares accessModeSufficient: textual while containing an unlabelled diagram is making a false accessibility claim, and under the Act that is a compliance statement rather than a nicety.

So the values have to be derived from the book, not stamped on it. This tool counts the images, checks whether each has alternative text, and writes metadata that matches: a book with three undescribed figures gets a summary saying three images do not carry alternative text. That reads as a worse file. It is a more useful one, because it is both correct, and the thing that prompts the author to go and write the alt text.

The stylesheet matters too

Two CSS declarations undo a great deal of accessibility work, and both are common in self-published EPUBs:

• A font size in points or pixels. A reader with low vision has set a size on their device. A stylesheet that overrides it takes that away, which is precisely the adjustment the whole reflowable format exists to allow.
• A text colour or a background colour. A book specifying color: #000 is unreadable in night mode: the reading system darkens the background and the text stays black. Readers who need high contrast are exactly the ones this breaks.

Neither is needed for a book of prose. An ebook stylesheet should set the relationships (indents, space, what a scene break looks like) in relative units and leave the absolutes to the reader.

How to check

• Ace by DAISY is the free accessibility checker for EPUB. It reports what is missing and what is asserted falsely.
• EPUBCheck validates the package itself. Not an accessibility tool, but a file that does not validate cannot be relied on to do anything.
• Turn on your phone’s screen reader and read a chapter. Ten minutes of this teaches more than either tool. You will hear the ornament described twenty times, and you will hear where the reading order goes wrong.

This tool writes the structure and derives the metadata. It does not run Ace, and it does not claim conformance to a WCAG level, because conformance is a judgement about content as much as structure, and no formatter can make it for you.