The conformance checker for EPUB publications

EPUBCheck is a command line tool. Unzip the downloaded package, open a terminal program, and start checking your EPUB files!

epubcheck moby-dick.epub
Validating using EPUB version 3.3 rules.
No errors or warnings detected!

Learn more on how to get started.


Open Source.

EPUBCheck is open source, licensed under MIT.

EPUBCheck is a W3C project maintained by the DAISY Consortium.


EPUBCheck evaluates EPUB publications against the official EPUB specifications.

It supports both EPUB 2 and EPUB 3.


EPUBCheck is translated in a varierty of languages.

You can help to contribute to the localization effort!

Looking for an app?

EPUBCheck is distributed as a command line tool or a Java library.

If you prefer using an app, see this list of third-party tools integrating EPUBCheck!