Voting Underway to Approve EPUB 3.1 Update

December 13, 2016
The IDPF Board has called a vote of the IDPF membership to approve  EPUB 3.1 as the new current version of EPUB. Voting will be open through January 3, 2017.

The EPUB 3.1 project began in October of 2015, with a goal of simplifying the specification and better aligning with the Open Web Platform. EPUB 3.1 is a significant update but includes no significant new features: it addresses many errata and other minor issues, reflects updates to HTML5 and other Web specifications since the finalization of EPUB 3.0.1 in June, 2014. and adds specificity to accessibility requirements. Additonally, the EPUB specification has been significantly reorganized, with  general conformance requirements now a separate document that also serves as the main "entry point" to the EPUB specification.

The EPUB 3.1 revision also introduces a new accessibility specification and a non-normative accessibility  techniques document. Although developed as part of EPUB 3.1 and to provide guidance on making conforming EPUB publications accessible, these new documents are designed to be equally applicable to older versions of EPUB 3. 

The specification documents which comprise EPUB 3.1 are:

(EPUB Accessibility Techniques 1.0, a non-normative proposed Informational Document, is not considered part of EPUB 3.1 per se and thus is not part of the current vote)

Three informal Editor's Drafts were published, followed by a formalPublic Draft and then advancement to Proposed Specification status for a final member and public review and comment period that began October 14, 2016,  according to the IDPF Policies and Procedures and Intellectual Property Policy No subsequent material changes were made en route to the recommendation of the EPUB Working Group to proceed to a final vote, although a number of minor issues were addressed.

The Working Group leadership has concluded that because of the very limited normative changes in the EPUB 3.1 update there should not be significant issues in it being rapidly adopted as the current version of EPUB. It is anticipated that EPUBcheck will be updated to support validation of EPUB 3.1 and that EPUB 3.1 tests will be added to the EPUB Test Suite according to schedules that would be developed after the specification is approved. The Readium team does not believe changes are required for its open source implementations of EPUB rendering to function properly with EPUB 3.1 content.

For more information about EPUB 3.1 see the project home on GitHub. More information on all IDPF specification development activities is available at

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