Validate an EPUB file
Find out exactly why a store or reader is rejecting your book.
How to check an EPUB for problems
- 01 Choose your EPUBDrop the file above or tap to pick one from your device.
- 02 Read the reportErrors break the file. Warnings will still open, but are worth fixing.
- 03 Fix and re-checkMost problems are missing metadata or files listed but not included.
Errors vs warnings
A missing mimetype, a broken container, absent required metadata, or manifest entries pointing at files that are not in the archive.
No navigation document, or an EPUB 2 package. The book opens, but the table of contents may be empty and some stores will complain.
Questions
Is this the same as EPUBCheck? ＋
No. EPUBCheck is the official, exhaustive validator. This runs the structural checks that catch the overwhelming majority of real rejections, instantly and without uploading your file.
It passes here but my store still refuses it. ＋
Stores add their own rules on top of the spec — cover dimensions, metadata completeness, file size. Check their guidelines next.
Are my files private? ＋
This tool runs entirely inside your browser — your file is never uploaded anywhere. It stays on your device, and closing the tab is all it takes to remove it.
Is it really free? ＋
Yes. Every tool, every file size, no account. There is no paid tier and nothing is held back.
Does this work with DRM-protected books? ＋
No. Files with DRM can’t be opened by any converter. This tool works with DRM-free files — like the ones you export from your own writing tools or buy from DRM-free stores.