Common EPUB Problems
1. Broken Table of Contents
Symptoms: TOC doesn't appear or links don't work
Solutions:
- Regenerate TOC in Calibre or your EPUB editor
- Ensure chapter headings use proper HTML heading tags (h1, h2)
- Check that nav.xhtml or toc.ncx file is properly formatted
2. Images Not Displaying
Symptoms: Blank spaces where images should be
Solutions:
- Verify image files are included in EPUB package
- Check image paths in HTML (should be relative)
- Ensure images are web-compatible formats (JPG, PNG)
- Compress large images (under 5MB each)
3. Font Issues
Symptoms: Text appears in wrong font or missing characters
Solutions:
- Embed fonts properly in EPUB structure
- Use web-safe fonts as fallbacks
- Check font licensing (must allow embedding)
- Test special characters display correctly
4. Spacing and Indentation
Symptoms: Inconsistent paragraph spacing, missing indents
Solutions:
- Use CSS for consistent styling
- Remove hard tabs, use CSS text-indent
- Clear any Word document formatting artifacts
- Use margin and padding consistently
5. Page Breaks in Wrong Places
Symptoms: Chapters break mid-page or don't break
Solutions:
- Use proper CSS page-break-before/after properties
- Start each chapter in a new HTML file
- Remove manual page breaks from source document
Validation Tools
EPUBCheck
Industry standard EPUB validator:
- Download from GitHub (free)
- Command-line or desktop app versions available
- Identifies structural errors and compliance issues
- Must-use before uploading
Calibre's Edit Book Feature
- Built-in EPUB editor
- Visual preview while editing
- Check Book function finds common errors
- Can fix many issues automatically
Testing Your EPUB
Before uploading, test on multiple devices/apps:
- Apple Books: Mac or iOS device
- Google Play Books: Android app or web
- Calibre: Desktop e-reader app
- Adobe Digital Editions: Industry standard reader
Getting Professional Help
If you can't fix formatting issues:
- Hire a professional formatter (Reedsy, Fiverr, Upwork)
- Use formatting software (Vellum, Atticus, Reedsy)
- Contact support for file review