Publishing standards

Know which standard is current, which one is emerging, and which rules belong to retailers.

Standards are the foundation; retailer requirements sit on top of them. EbooksLaunch separates those layers so authors can make better production decisions.

Current baseline: EPUB 3.3 is a W3C Recommendation. EPUB Accessibility 1.1 is a W3C Recommendation. EPUB 3.4 and EPUB Accessibility 1.2 are newer candidate-recommendation work as of 2026, so production decisions should distinguish stable recommendations from emerging drafts.

EPUB 3.3

The stable W3C Recommendation defining the EPUB 3 publication format and authoring requirements.

W3C specification →

EPUB Accessibility 1.1

The stable W3C Recommendation covering accessibility conformance and accessibility metadata for EPUB publications.

W3C specification →

EPUB 3.4

Emerging work in the EPUB standards family. A candidate recommendation is not the same thing as the stable recommendation used as a production baseline.

W3C EPUB status →

Retailer requirements

Amazon, Kobo, Apple, aggregators, and library channels can impose additional requirements or preferences. Those are platform rules, not replacements for the EPUB standard.

Retailer guidance →

Primary sources

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