EPUB vs MOBI vs AZW3: Converting E-Book Formats
Compare EPUB, MOBI, and AZW3 e-book formats. Learn which format works best for Kindle, Kobo, iPad, and how to convert between them.
Understanding E-Book Formats
E-books come in many formats, but EPUB, MOBI, and AZW3 are the most common. Each has its own strengths and device compatibility. Knowing which format to use — and how to convert between them — ensures your books look great on any device.
EPUB (Electronic Publication)
Best for: Open-standard e-reading across multiple platforms
- Open standard supported by almost all e-readers except older Kindles
- Reflowable text that adapts to any screen size
- Supports images, CSS styling, and basic JavaScript
- DRM-protected and DRM-free versions widely available
- Supported by Kobo, Apple Books, Google Play Books, and most apps
MOBI (Mobipocket)
Best for: Legacy Kindle devices
- Older format based on HTML 3.2
- Supported by older Kindle devices and the Kindle app
- Limited CSS support — simpler formatting
- Being phased out in favor of AZW3 and KFX
- Still widely used for e-book distribution
AZW3 (Kindle Format 8)
Best for: Modern Kindle reading experience
- Amazon's proprietary format for Kindle devices
- Better typography and layout than MOBI
- Supports HTML5, CSS3, and enhanced formatting
- Faster page rendering and better image handling
- Can be converted to EPUB for use on other devices
Device Compatibility
| Device/App | EPUB | MOBI | AZW3 |
|---|---|---|---|
| Kindle (Modern) | No* | Yes | Yes |
| Kobo | Yes | No | No |
| Apple Books (iPad/iPhone) | Yes | No | No |
| Google Play Books | Yes | No | No |
| Calibre (Desktop) | Yes | Yes | Yes |
* Kindle supports EPUB via email-to-Kindle or Send to Kindle feature
Converting Between Formats
- Upload your e-book file — drag and drop your EPUB, MOBI, or AZW3 file
- Select target format — choose the format compatible with your device
- Convert — formatting and images are preserved during conversion
- Download — transfer the converted file to your e-reader
GoConvertFile converts your e-books instantly while preserving formatting and images. Try our EPUB to MOBI converter, MOBI to EPUB converter, or EPUB to AZW3 converter — free and secure.