📌 Article Summary
MOBI is an ebook format originally developed by Mobipocket and later acquired by Amazon. While Amazon has gradually moved to AZW3 and KFX formats, MOBI remains important for sending personal ebooks to Kindle devices.
What is MOBI Format?
MOBI is an ebook format developed by Mobipocket SA, with the file extension .mobi. Amazon acquired Mobipocket in 2005, and MOBI became one of Kindle's standard formats.
MOBI is based on the Open eBook (OEB) standard, using HTML for content and supporting JavaScript, frames, and complex formatting.
MOBI, AZW, AZW3: What's the Difference?
As a Kindle user, you may encounter several similar formats:
| Format | Description | DRM | Features |
|---|---|---|---|
| MOBI | Original Mobipocket format | Optional | Basic format, good compatibility |
| AZW | Amazon's MOBI variant | Usually yes | MOBI with Amazon DRM |
| AZW3/KF8 | Kindle Format 8 | Usually yes | HTML5/CSS3 support, richer features |
| KFX | Latest Kindle format | Yes | Enhanced typography, best experience |
💡 Simple Explanation
MOBI is the base format, AZW is MOBI with DRM, AZW3 is the enhanced version, and KFX is the latest and most advanced. For personal use, MOBI and AZW3 are most common.
How to Send MOBI Files to Kindle
Although Amazon stopped email support for MOBI in 2022, you still have options:
Method 1: USB Transfer
- Connect Kindle to computer via USB
- Kindle appears as removable drive
- Copy MOBI file to
documentsfolder - Safely eject device, book appears on Kindle
Method 2: Send to Kindle App
- Download Amazon's Send to Kindle app
- Drag ebook files to app window
- Select target device, click send
- Tip: Use EPUB format for auto-conversion
Method 3: Kindle Email (Recommend EPUB)
- Find your Kindle email in Amazon account settings
- Send EPUB file as attachment to that address
- Amazon auto-converts and delivers to device
Converting MOBI Files
You may need to convert MOBI in these situations:
- EPUB to MOBI: Read EPUB on older Kindles
- MOBI to EPUB: Read on non-Kindle devices
- MOBI to AZW3: Better formatting
- PDF to MOBI: Better PDF reading on Kindle
🔄 Need to Convert Ebook Formats?
Our free tool converts between MOBI, EPUB, PDF, AZW3 and more
Convert Now →Frequently Asked Questions
Q: Is MOBI or EPUB better?
For Kindle, both work (EPUB is auto-converted by Amazon). For other devices, EPUB is more universal. Feature-wise, EPUB 3 offers more capabilities.
Q: Why did Amazon stop email support for MOBI?
Amazon wants users to use the more modern EPUB format, which they auto-convert to optimized Kindle format for better reading experience.
Q: Can old Kindles still use MOBI?
Yes. USB transfer still works, and all Kindle devices support MOBI format.
Conclusion
While MOBI is being replaced by newer formats, it still has an important place in the Kindle ecosystem. For users with large MOBI collections, these books remain fully usable.
For new ebooks, we recommend EPUB format as it's more universal and Amazon auto-converts it to the best format for your device.