# What is EPUB 2?

Source: https://epubcc.com/glossary/epub-2/ (updated 2026-11-04)

EPUB 2 is the previous generation of the EPUB standard (2.0.1 dates from 2010), based on XHTML 1.1 and an NCX table of contents. It has been superseded by EPUB 3 but many older files still use it.

## Why it matters when you convert a PDF to EPUB

There is no reason to produce EPUB 2 from a PDF today: current readers, Send to Kindle and Kobo all accept EPUB 3. EPUB 2 matters when you validate or repair older files, because EPUBCheck validates them against the EPUB 2 rules and reports messages that only apply there, such as NCX identifiers.

How EpubCC handles it: it never writes EPUB 2. Its output is EPUB 3 only, without an NCX, which current reading apps, Send to Kindle and Kobo devices accept. If you need to validate or fix an EPUB 2 file you already have, the EPUBCheck reference on this site explains the messages that only apply to EPUB 2, such as the NCX ones.