Supported EPUB files

For the best results, use a standard, DRM-free EPUB with a valid table of contents and readable text chapters.

Requirements

• File extension: .epub
• Media type: EPUB
• Maximum upload size: 50 MB
• Valid EPUB ZIP structure
• At least one readable section

Unsupported or problematic files

The app may reject:

• encrypted or DRM-protected books;
• corrupt or incomplete EPUB archives;
• files with unsafe archive paths;
• EPUBs with invalid metadata or no readable sections;
• another format renamed to .epub.

When a book does not open

Try opening the EPUB in another reader first. If it also fails there, obtain a fresh copy from the publisher or export the source document as EPUB again.