*2023 Update- Mobi is on its way out!
Azw, kpf, pdf, epub and mobi... At least there is one less file to worry about going forward. Mobi will officially start disappearing soon. Well, it should've already...
Amazon announced that it would not allow authors to publish books in the mobi format from 1 August 2022. It also stated that it would discontinue mobi files for the side-loading of books, better known as the Send to Kindle service.
At the time of publishing this update (February 2023), it was still possible to do so, but a warning message appeared from the app stating that this service would be canceled soon.
So, if you are keen to learn a bit more about the history of the various file formats, then please continue reading. But for those that wanted to know if they should still use mobi, the answer is a big NO.
EPUB is the way forward for now...
What is the difference between epub and mobi?
Firstly, let’s assume that your book does not contain lavish photos, drawings, and diagrams. For that reason, we will not be focusing on the pdf format in this article.
The most common eBook reader formats are epub and mobi. The main differentiator between these two formats is that epub is open source and is supported across most platforms while mobi is a proprietary format primarily used for Amazon Kindle. Let’s put both under the microscope separately.
As stated before, the epub (stands for electronic publication) format is suitable for most platforms and these include the big players such as Amazon, Apple Books, Kobo, Barnes and Noble Press, and Google Play Books. In fact, there are close to 300 platforms that are epub-friendly. It was created by the International Digital Publishing Forum and is updated frequently to keep up with emerging trends in the consumer sphere as well as advancements in tech. EPUB 3.2 was released in 2019 and The Book Industry Study Group has endorsed EPUB 3 as the format of choice for eBooks worldwide.
Mobi (short for the Mobipocket eBook format) is basically the grandfather ghost of an eBook company that Amazon bought long before Jeff Bezos had sufficient money to consider space exploration as a hobby.
The original Mobi file format is almost non-existent but its grandchildren, AZW, AZW3, and KFX are alive and well on the Amazon Kindle device. Many people still use the word “mobi” when they refer to these Kindle ebook formats.
I know you are burning to find out which one to choose but hang in there! We will get there soon.

Can epub be read on Kindle?
In short, epub formats CAN'T be read by Kindle or a Kindle ereader. Kindle reads specific mobi descendant files (AZW format etc) and epub is not one of them. Thanks to modern technology, we have a solution for you that would make you jump with joy.
Can you convert epub to mobi?
If you are an avid reader and you just love taking your Kindle everywhere you go, but you have a few books that are in epub format, here is some exhilarating news for you! You can convert epub into mobi by using ebook conversion tools such as Calibre, Convertio, Cloudconvert, etc if you want to read these files on your Kindle.
If you are a writer and you are concerned about your epub format manuscript, here is some other great news for you. Amazon did not accept epub formats in the past, but they evolved and today, you can upload your epub manuscript and they will convert it into mobi in the background so that readers can enjoy your book on Kindle.
What are the pros and cons of epub and mobi?
Now that you know a little more about where these formats come from, and what they stand for, let’s consider the pros and cons of epub and mobi so that you can decide which is best for you.
Epub pros and cons:



Have you ever opened a PDF file on your phone? Do you remember how your fingers were more active than when scrolling through Tinder on a lonely Friday evening? You scrolled and zoomed and panned, and the whole process left you a little short of carpal tunnel syndrome.
The reason why is that the pdf document is not reflowable like epub, it has a fixed layout format. Reflowable means that the epub format adjusts to the device you are using at the time so that you can enjoy the most hassle-free reading experience with the reflowable content.
Epubs are easier to use than most other eBook formats. Not only are they reflowable which makes life easier for the reader, but they are easy to create and edit.
Almost all publishers accept epub books in their marketplaces.
Apart from Kindle, almost all other eBook readers will open epub. These include Nook, Andriod, Sony Reader, Apple's ibook, Adobe Editions, etc.
You can give life to your book by adding multimedia files such as tutorial videos, illustrations, etc in the epub format.
When you are using Google Docs, you can download an epub book, unlike the mobi derivatives. Large docs are no problem for epub either.
And now for the ‘but’.
As stated before, your Kindle device or Kindle app will pull up its nose to your epub file like some spoiled kid that just got served a good helping of broccoli. In case you skimmed past this information before, here is another reminder that you can easily use an eBook converter and convert the files yourself and Amazon also auto-converts them when you upload epub files.
Digital rights management or DRM for short is an optional anti-piracy layer in epubs and they are not present in all epubs.
Mobi pros and cons:



Mobi (or rather AZH and KPF) are the exclusive formats for Kindle. If you want to read your book on your Kindle, it has to be in the Mobi format.
Amazon uses Mobi format in its marketplace, but it will accept your epub manuscript and then convert it to mobi.
You can convert mobi to epub if you wish using free converter software.
Mobi files are safer seeing that they include a digital rights management (DRM) layer that protects your book from pesty pirates.
But…
Mobi is predominantly a Kindle format and is not welcome widely in other marketplaces. This, along with the fact that Amazon will convert your epub file anyway, deters most writers from creating mobi legacy format books.
The verdict of epub and mobi formats
Here is our Golden Rule for eBook format selection: Find out which marketplace would be best for you and create the eBook according to their requirements.
Epub format is the biggest vendor-independent format and is also the most read format in the world. The easiest would be to have an epub formatted book and then convert it to mobi if you have to. As stated before, Amazon will do it for you anyway if you desire to sell it there.
Have you published a book before, and did you face any challenges when it came to epub and mobi formats or do you have some advice to share? Please be so kind as to share your thoughts and opinions on our social media platforms or contact us directly.