Supported File Formats
EPUB requirements and cover image specifications for ebook distribution.
eBook File Format: EPUB Only
Shelf Indulgence accepts EPUB files only for ebook distribution. EPUB is the industry-standard format supported by all major retailers including Apple Books, Google Play, Kobo, and OverDrive.
- Format: .epub files only
- Maximum size: 100MB
- Version: EPUB 2.0 or 3.0
- Validation: Files should be error-free and validated
Creating EPUB Files
Professional Tools:
- Calibre — Free, open-source ebook management tool with EPUB creation
- Vellum — Mac-only paid software for professional ebook formatting
- Atticus — Cloud-based writing and formatting software
- Reedsy Book Editor — Free online book formatting tool
Conversion Services:
- Draft2Digital — Free DOCX to EPUB conversion
- Reedsy — Free formatting and conversion services
- Professional formatters — Hire specialists on Reedsy, Fiverr, or Upwork
Important: Shelf Indulgence does NOT convert DOCX, PDF, or MOBI files to EPUB. You must upload a completed, validated EPUB file.
EPUB Validation
Before uploading, validate your EPUB to catch errors:
- EPUBCheck — Industry standard validator (free, open-source)
- Calibre's built-in validator — Quick check within Calibre
- Online EPUB validators — Web-based validation services
Common EPUB Errors:
- Broken internal links
- Missing or incorrect metadata
- Invalid HTML/CSS
- Improper table of contents
- Font embedding issues
Cover Image Requirements
| Specification | Requirement |
|---|---|
| Recommended size | 1600x2400px |
| Aspect ratio | 2:3 (portrait) |
| Maximum file size | 10MB |
| Minimum resolution | 72 DPI |
| Color mode | RGB |
| Supported formats | JPG, PNG |
Audiobook Formats
Audiobook distribution is currently in production. Supported formats will be:
- MP3 or M4A audio files
- Square cover image (3000x3000px)
- Chapter markers
Troubleshooting Upload Issues
EPUB Upload Fails:
- File larger than 100MB — compress images within the EPUB
- File corrupted — run EPUBCheck and fix validation errors
- File not actually EPUB — ensure .epub extension is correct
- Network timeout — try uploading again with stable internet
Cover Upload Fails:
- File larger than 10MB — compress or resize the image
- Wrong format — convert to JPG or PNG
- Dimensions too small — resize to at least 1600x2400px
Full guide to uploading books | Cover design best practices | Detailed upload error troubleshooting