Glossary · Accessibility term
EPUB accessibility
EPUB accessibility is what an e-book has to do to be readable by everyone who buys it, and the standard that says so is EPUB Accessibility 1.1, a W3C Recommendation dated 17 October 2024. It does two jobs rather than one. It sets conformance requirements for the content. And it sets metadata requirements, so a reader can find out whether a book works for them before opening it, which is something WCAG has no equivalent for. The floor is lower than most people assume. A publication has to meet WCAG 2.0 at Level A, and the latest version of WCAG at Level AA is only strongly recommended. So a title can conform to the standard and still fall short of what a contract or a law is asking for.
In practice
EPUB 3 is packaged HTML underneath, so the work is the work you already know. Real headings, alt text, language attributes, a reading order that means something. What differs is the metadata. Three fields are required, naming the senses or faculties somebody needs to take in the content, the accessibility features the book carries, and the hazards it presents. Two more are recommended, including a summary written for a person to read and a statement of which combinations of senses are sufficient on their own. A conformance claim lives in the metadata too, in a separate field naming the standard the book was assessed against, with another beside it naming who did the assessing.
The hazard field is the genuinely different idea. Where WCAG prohibits flashing above the threshold, EPUB asks you to declare flashing, motion simulation and sound up front. A reader who has to avoid them can then decide before opening the book rather than after. That is a different model from the web's, and it only works if the field is filled in honestly.
The law arrives by a separate door. The European Accessibility Act brought e-books into scope as a service from 28 June 2025. It put e-readers in scope as a product, on a different track with different duties, so a publisher and a device maker face different obligations under one directive. Two things answer most publishers' first question. A microenterprise providing a service is exempt outright, meaning fewer than 10 staff and a turnover or balance sheet total not exceeding EUR 2 million. And the directive names particular exclusions rather than a blanket cut-off date, archived material nobody has updated among them, so read the list before assuming your backlist is outside. The route matters too. An obligation reaching you through the European technical standard rather than through EPUB Accessibility names a different version of WCAG.
Why it matters
Ask which bar you are being held to before you sign anything. EPUB Accessibility 1.1 requires WCAG 2.0 at Level A and recommends more. A European buyer working from the standard in force there is asking for WCAG 2.1 at Level AA. Those are different answers to the same question. A title that satisfies the first can fail the second. Books are also the format where an accessible version changes what somebody can do rather than making an existing task smoother. And the technical work is mostly the work of making a web page accessible.
Two bars, one book
A publisher certifies a title as conforming to EPUB Accessibility 1.1, having met WCAG 2.0 at Level A, which is what that standard requires. A European buyer working from the European standard is asking for WCAG 2.1 at Level AA. Both statements are accurate and they are not describing the same book.
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Related terms
- European Accessibility ActThe European Accessibility Act is the EU law that has required certain consumer products and services to be accessible since 28 June 2025, and the word to hold onto is certain.
- PDF/UAPDF/UA is the international standard for accessible PDF, published as ISO 14289 in two parts.
- Tagged PDFA tagged PDF carries an invisible structure layer naming each part of the document.
- Heading structureHeading structure is the h1 to h6 outline of a page, and for screen reader users it is the map.
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