Looking for updates? Subscribe to our newsletter

EPUB vs mobi: Which eBook Format Should You Use?

Posted in: Book Design, Understanding Publishing on November 17, 2017 6 Comments 💬

epub pdf mobi

EPUBs and mobi files are the most common ebook formats in the world. If you're a self-publishing author looking to distribute your title in ebook stores (which you should: some of the most voracious readers own e-readers) you will need to know a little about these two file types. In this post, you will learn everything you need to know about the Clash of the Titans that is epub vs mobi.

What is an EPUB?

An EPUB file is the most widely-accepted ebook format on the market. It’s the industry standard, used by Apple, Kobo, Barnes & Noble, Sony and Google e-readers.

A free and open standard based on HTML (much like the files your web browser would read), EPUB is a remarkably flexible format that supports a wealth of features. It can optimize a book’s text to fit your device, embed images, and allow for bookmarking, highlighting and text-to-speak. The latest version, EPUB 3, will even permit you to add multimedia content like video and audio clips.

All around, it’s pretty great — which is why the publishing industry has rallied around it as its ebook format of choice. If you want to upload your book directly to almost any ebook retail platform – through Kobo Writing Life or Nook Press, for example – or use an ‘aggregator’ like Smashwords or Draft2Digital, you will need to have an EPUB file.

So what’s stopping EPUB from being the single digital book format?

What is a mobi file?

Does Moby prefer mobis to EPUBs? One can only assume.

Mobi files are the ebook files used exclusively by Amazon’s Kindle Store. Or, if we're staying up-to-date, the actual proprietary standard is now called AZW. The major difference between mobi files and EPUBs is that the Amazon format is protected by Digital Rights Management (DRM) which ‘locks’ the book so it can only be read on devices associated with your account. Amazon is the largest ebook retailer in the world by quite a long way: in 2015 they were responsible for over 70% of ebooks sold in the US. This massive market share is part of the reason why they can insist on using their own format.

To summarize: the Kindle store uses mobi files, and every other major ebook uses EPUBs. But, if you're an author looking to export an ebook file that's compatible everywhere, what can you do? Well, the short answer is that you should export an EPUB, for reasons we'll look at right now.

Learn the trade tricks to self-publishing a book

Sign up for this free 10-part course! Enter your email below and select 'Publishing - Self-Publishing 101' in the drop-down menu.

What's the easiest way to convert EPUB to mobi?

If you have an EPUB that you want to convert to mobi right now, you can simply put it through our EPUB to mobi converter! You'll get a beautiful new mobi file in your email inbox within minutes.

Amazon's Kindle Direct Publishing platform also has an integrated tool which will convert EPUBs into mobi files. The Reedsy team ran countless tests and found the conversion to be pretty seamless.

Finally, if you export an ebook using the Reedsy Book Editor, you will have the option to choose your ebook retailers. If you select 'Amazon' as an option, you will download your book in mobi format.

When should you use PDF files?

The PDF, which has remained one of the most popular document formats since its debut in 2001, is still widely used in publishing for two purposes.

Perhaps the most cost-effective way of selling physical copies on a small scale, self-publishing authors commonly use what’s called a print-on-demand (POD) service. Instead of ordering a print run and filling a warehouse with paperbacks, copies will only be printed as and when they’ve been purchased either by individual buyers or a bookstore.

The two most popular POD services are IngramSpark and KDP Print (formerly CreateSpace), the latter of which is — would you believe it? — an Amazon company.

A print-on-demand book, sourced from a PDF file.

For this, you will need a file that contains strict definitions of your book’s layout and content – which is why we use PDF files. There are countless different types of PDF out there but for our purposes, the format will need to a ‘print-ready PDF’ to make it compatible with printers.  Any hyperlinks will be removed and your image colors will be expressed in CMYK, and not using the RGB color model.

Graphically Intensive eBooks

Both EPUBs and mobis are great at handling text-intensive books like novels, memoirs and some non-fiction books. They are, however, less awesome at dealing with books that have a lot of images, graphs and photos — art books and travel guides, for example. If you need your ebook to look exactly the same as the print version, you may wish to sell it as a PDF, which will ensure fidelity across all devices.

The downside is that basic black-and-white Kindles (and e-readers like it) will struggle to display them well — as these PDF books will tend to be fixed-width. Unlike an EPUB file, where the text is "reflowable" and will adapt to the shape and size of your device, reading a small-print PDF book on a Kindle Paperwhite is nothing short of a chore.

Creating EPUBs and print-ready PDFs

Reedsy offers a free online book editing tool that lets you professionally format a book with no training required. Once you’re happy with how it looks, you can export your book for free as both EPUB and print-ready PDF files!

To find out more about how the Reedsy Book Editor can help you publish your own book, click here.

To learn more about how to set up your ebook on the different retailers, read our master guide on ebook publishing platforms.

If you have any thoughts or questions on choosing a file format, drop us a message in the box below.

Leave a Reply

5 Comment threads
1 Thread replies
Most reacted comment
Hottest comment thread
6 Comment authors
newest oldest
Notify of
Henrique Pereira


Leslie Baldwin

Which format supports an eBook where the reader can type in the book, such as a journal. I know a fillable text PDF will, but what about the other two eBook formats?

one if the most complete articles i have ever read about ebooks

A big help. People seem to really like messing up the question with messy answers.

thanks for a great explanation. I tried making an epub book and its look great, but it omitted all of my jpg files. How do I edit the epub so I can insert my images? Do i use a separate app or can it be done on reedsy?

Continue reading

Recommended posts from the Reedsy Blog

How to Self-Publish a Book on Amazon

So, you're an independent author who's ready to put out your newest work — and now you want to know how to publish a book on Amazon, the grand hub of e-commerce and the original …

Read article

Manuscript Format: A Guide for Novels (FREE Template)

When you’re writing a first draft that’s for your eyes only, there’s no “wrong” manuscript format. Whatever helps you get your ideas down is perfectly fine — and don’t let anyone tell you otherwise. Some …

Read article

The Best Free Book Cover Makers (and a Few Paid Ones)

If you're on the hunt for some free book cover makers, you're probably looking to DIY the cover for your book. But before we get to our recommendations, we should start with a caveat: if …

Read article

How Much Does It Cost to Self-Publish a Book in 2019?

We all know that writing and publishing a book is a costly process — not just financially, but emotionally, too. And even once you’ve emerged from self-imposed writing exile with your hard-earned manuscript in hand, …

Read article

50 Best Writing Websites of 2019

The Internet is full of writing websites and blogs to help people reach their creative goals. If you’ve always dreamt of writing your own book, but don’t know how to get there — or if …

Read article

Authors Beware: Scams and Publishing Companies to Avoid

Becoming a published author is a fantasy shared by almost all writers. And as with almost any widely-shared ambition, there are also folks out there looking to make a quick buck by exploiting those dreams …

Read article
modal book launch checklist
Download The Book Launch Checklist