EPUB vs MOBI: which format should you use?
EPUB and MOBI are both reflowable ebook formats, but their trajectories are opposite. EPUB is the modern industry standard supported by every non-Kindle e-reader. MOBI is Amazon's original format, technically still supported by Kindle but largely superseded by AZW3 for new sideloads. In 2026, EPUB is the right default for most people; MOBI is legacy.
Head-to-head comparison
| Aspect | EPUB | MOBI |
|---|---|---|
| Origin | International standard (2007) | Mobipocket, Amazon (2000) |
| Reflowable | Yes | Yes |
| Native reader | Apple Books, Kobo, Google Play | Kindle (legacy) |
| Kindle support | Yes via Send-to-Kindle | Yes but AZW3 preferred |
| Fixed layout option | Yes | Limited |
| DRM | Optional (Adobe ADEPT) | Optional (Amazon's system) |
| Metadata + cover art | Rich | Basic |
| Best for | Everything except old Kindles | Legacy Kindle libraries only |
When to use each
Use EPUB when
- You want a format that works on every non-Kindle e-reader
- You're publishing an ebook and picking one format
- You're archiving a library for long-term readability
- You're sending books to friends who don't use Kindle
Use MOBI when
- You're dealing with pre-2018 Kindle purchases
- You have a legacy MOBI library you're maintaining
- A specific legacy Kindle device requires it
The verdict
In 2026, EPUB is the answer for almost everyone. Amazon's Send-to-Kindle now accepts EPUB directly, so even Kindle owners don't strictly need MOBI or AZW3 anymore. Convert MOBI collections to EPUB for a future-proof library — the reverse conversion (EPUB to MOBI) only makes sense for specific legacy Kindle workflows.
Frequently asked questions
Is MOBI dead?
Effectively, yes. Amazon deprecated MOBI in 2022 and stopped accepting new MOBI uploads to Kindle Direct Publishing in August 2022. New Kindles still open MOBI files you already have, but Amazon now converts everything to KFX/AZW3 internally. For new libraries, EPUB is the future-proof choice.
What's the difference between MOBI, AZW, AZW3, and KFX?
All Amazon Kindle formats. MOBI (2000) was the original — bought by Amazon in 2005. AZW (2007) added Amazon DRM to MOBI. AZW3/KF8 (2011) added modern features like CSS3 and fixed-layout. KFX (2015) is Amazon's current format with better typography. Converting between them requires Amazon's tools or Calibre.
Can non-Kindle readers open MOBI?
Some. Calibre reads and converts MOBI. Kobo devices don't support MOBI natively — you'd convert to EPUB first. Apple Books doesn't open MOBI. Google Play Books doesn't either. If you're moving away from Kindle, converting MOBI to EPUB is the standard migration step.
Does converting MOBI to EPUB preserve highlights and bookmarks?
No. Highlights and bookmarks are stored in the Kindle app's local database, not inside the MOBI file. Converting the file doesn't migrate them. Amazon does offer highlight export via kindle.amazon.com for your Amazon account; you'd import those separately into your new reader.
Which format has better typography?
EPUB 3, generally. It supports full CSS3, custom fonts, and modern typography features (hyphenation, drop caps, ligatures). MOBI's CSS support is basic and buggy on older Kindles. AZW3 improved this but still lags EPUB 3. For beautifully typeset books, EPUB is the format to buy.
How do I send an EPUB to my Kindle now?
Three ways: email it to your Kindle Send-to-Kindle address (found in Amazon's Manage Your Content settings); use the Send-to-Kindle app on Windows/Mac; or connect the Kindle via USB and drag the EPUB to the documents folder. Amazon converts it to KFX for display on delivery.
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Last reviewed: Sept. 12, 2026