EPUB error checker
Validate an EPUB and download a report of structural errors and warnings.
Your results
EPUB error checker
Find packaging and structural problems in an EPUB before distributing the ebook. The validation report identifies errors and warnings to investigate in your editing software. Recheck the corrected file and preview it in the intended reading application.
How to use this tool
- Choose your source file, drag it into the upload area, or import a direct public file URL.
- Review the settings and create your result.
- Download and check the output before using it.
Supported input formats
EPUB
Output and limitations
Validate an EPUB and download a report of structural errors and warnings.
Uses EPUBCheck. A passing structural check does not guarantee accessibility or acceptance by every bookstore.
Where are my files processed?
On the configured processing server. Your browser uses a private job token to retrieve the result. Files are automatically removed after expiration or when you download the result.
What if processing fails?
Check the supported formats and file limits, then try a smaller file. Keep an original copy. A clear error message will explain an unsupported input or an unavailable processing service.