# What is the EPUB navigation document?

Source: https://epubcc.com/glossary/nav-document/ (updated 2026-11-04)

The navigation document is the XHTML file that holds an EPUB 3's table of contents, as a nav element with epub:type="toc", and optionally landmarks and a page list. Every EPUB 3 must have exactly one, marked with the "nav" property in the manifest.

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

This is where the chapters EpubCC detects in a PDF become a clickable table of contents on the reader. The entries must point to documents inside the EPUB and follow the reading order, and a page list must be there when the content marks printed page breaks.

How EpubCC handles it: nav.xhtml lists every chapter and, inside each chapter, the headings of the next level down (up to 200 per chapter), each linking to an anchor in the chapter file. Chapters come from the PDF outline when it has one, otherwise from the first heading level that appears on at least two different pages.