First Editor's Draft of EPUB 3.1 Available for Review

February 1, 2016

The EPUB 3 Working Group is pleased to announce that the first Editor's Draft of EPUB 3.1 is now available for community review. A condensed summary of the changes being put forward for review is available in the EPUB 3.1 Changes from 3.0.1 document. The approach taken in this first draft of propositioning potentially controversial changes, in effect as 'trial balloons",  makes timely feedback even more important. 

The primary thrust of this revision is to bring EPUB 3 more in line with the Open Web Platform (OWP). To that end, the HTML syntax of HTML5 is now proposed to have required support in reading systems. resulting in the need for a new cross-syntax compatible method to enrich the markup (i.e., that can work in HTML and XHTML). The working group is proposing a move to the ARIA role attribute coupled with the W3C Digital Publishing WAI-ARIA Module for semantics. This first editor's draft also proposes dropping support for EPUB 2 and for a number of EPUB 3 features that are not broadly compatible with the OWP.

A major reorganization of content is being proposed, with a new EPUB 3.1 top-level specification being added to provide a clear point of entry into the specifications. It defines the overarching publication and reading system requirements, and the EPUB Publications has been renamed to EPUB Packages with a focus on the package document and the construction of renditions of content.

The EPUB Style Sheets profile defined in EPUB 3.0 has similarly been a source of much confusion when it comes to what parts of CSS are supported. This section more clearly establishes the alignment of EPUB with the work of the W3C CSS working groups.

The EPUB 3.1 revision is also being taken as an opportunity to review the overall accessibility of the format. This draft proposes recommending that content documents meet WCAG 2.0 Level AA conformance requirements. 

For more information about all of these proposals, and others, please refer to the EPUB 3.1 Changes from 3.0.1 document. None of the decisions proposed in this draft are final, and all are open to be changed in future drafts. Those affiliated with IDPF member organizations are encouraged to join the IDPF EPUB Working Group email list to participate directly in the development process; feedback can also be provided via email  to the Working Group co-chair Markus Gylling -


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