EPUB to MOBI Converter

MOBI comes from Mobipocket, a company Amazon bought in 2005, and it was the format of the first Kindles. Later Kindles added Amazon's newer KF8 format, sold as AZW3, which handles fonts, spacing and images far better. MOBI stayed around for compatibility, and for years it was also the easiest way to email your own books to a Kindle.

That last role has ended. Amazon's Send to Kindle service no longer accepts MOBI files and takes EPUB instead, converting it for the reader on Amazon's side. So if your goal is to get an EPUB onto a current Kindle by email, the app or the website, you do not need to convert anything: send the EPUB as it is.

MOBI still makes sense in a narrower set of cases: an early Kindle that predates KF8, an old Kindle app or reading program that was never updated, or a reader from another brand that lists MOBI among its formats. In those cases you copy the file by USB cable, and that is what this page is set up for.

EPUB is maintained by the W3C, and the current version is EPUB 3.3. MOBI is far more limited in what it can display. Expect simpler formatting after the conversion: embedded fonts, detailed spacing and some styling fall back to the Kindle's defaults, while the text, chapters, images and table of contents come through.

Books you sent to a Kindle as MOBI in the past are a separate matter from new conversions. This page only changes how a new copy is made; it does not affect files already on your device or in your library.

If you are unsure which Kindle you have, the model name is in Settings → Device Info on the device. When in doubt, try AZW3 first: a Kindle that reads AZW3 shows a better-looking book, and one that does not will simply not list the file, in which case MOBI is the fallback.

Early Kindles have small, slow e-ink screens and little memory, so lighter books read better. The Kindle (basic) device profile sizes pages and images for that screen. Under Advanced settings you can also turn on Grayscale for images, which makes illustrated books smaller and avoids color images that the screen cannot show anyway.

Covers and contents deserve a check. With Cover on Keep cover, the EPUB's own cover becomes the thumbnail in the Kindle library; if a book has none, First image uses its first picture. The Table of contents option builds the chapter list that the Kindle's Go To menu shows, which is the main way to move around a long book on these devices.

Copy one book first and open it on the Kindle before converting a whole library. If chapters, images and the contents list look right, the rest will too.

You can convert up to 20 EPUB books at a time, each up to 95 MB, and each becomes its own .mobi file with the same name. Uploads are deleted after processing and the converted books 30 minutes later. The Ebook Converter handles every other target, including AZW3, PDF for printing and CBZ for comics, and PDF to EPUB turns a fixed-page PDF into a reflowable book first.