Metadata 101: What are the different kinds of eBook formats? And, how do I make eBooks?

‘American History Made Easy’ ebook on a Kindle Fire
Kathleen Gripman’s American History Made Easy is a wonderful choice for your Kindle. The book’s short, illustrated chapters are fun to read whenever you have a spare moment. Once you’ve bought the book in the Kindle format, you can easily read it on an actual Kindle device—or you can read it on the free Kindle device for your phone. Kindle will keep track of how far you’ve read across all your devices.

If a reader wants to read what you have written—we want to sell them a book as quickly as possible in whatever form they want. National trends show:

  • Book sales continue to rise each year. Three out of four Americans read books.
  • Young adults are driving sales. As a group, more people under age 50 read books every year than people over 50.
  • Impulse buying is big in selling eBooks. People hear about a book—and want it now! The number one eBook bestseller in  was Handmaid’s Tale. The other eBook bestsellers are a Who’s Who of top mystery writers from Michael Connelly to John Grisham. Big sales in eBooks are all about sparking curiosity—and immediately selling a book.
  • About 2 of every 10 books sold each day are eBooks. While that may sound like a small portion of sales—that means more than 160 million individual eBooks were sold in . No author wants to miss out on that market!

What Are the Different Kinds of eBooks?

There are four major eBook formats Front Edge routinely produces. Front Edge designers also produce a generic ePub file that is usable with any eReader device or associated software application. While many readers may not be aware of the specific technical differences between eBook formats, they likely have a preferred eReader. That’s why it’s important to optimize eBooks for different platforms.

Below is a breakdown of the differences between eBook formats. To read about the differences between different paper-bound editions, check out Part 3 of the Metadata 101 series.


Amazon’s Kindle is one of the most popular eReaders available, and the Kindle store sells millions of titles every month. While it’s not the most technically robust eBook format, Kindle books are specifically formatted to read well on the Kindle eReader and software. This includes complying with Amazon’s preview program that gives readers a peek into the book’s contents, as well as full compatibility with Kindle features like highlighter display and easy-to-use bookmarks.

Kindle books use a .mobi file type. This is a Kindle-exclusive file type. While it’s possible to convert the generic .epub eBook format into a .mobi file using Amazon’s own tools, it’s a good idea to create .mobi files without Amazon’s assistance to avoid conversion errors and other issues that will reduce a book’s readability.

When creating Kindle books, note that Amazon limits Kindle book file sizes to 650MB to ensure Kindle books are easy to purchase, transfer and borrow. Most books won’t test that limitation, but books with embedded audio and video can easily exceed 650MB. That’s why Front Edge Publishing designers prefer to link to media in a Kindle book, rather than embedding it directly. This means readers will need to have a wifi-enabled device or be able to go online to view audio and video contained in the book.


iBooks are specifically designed for optimal display and readability on iPads, iPhones and Apple computers. They are sold through the iBooks online store and application and are recommended for readers that prefer reading books using an Apple device.

iBooks have one big advantage over Kindle books from a publisher’s point of view: the limit for an iBook is 2GB, significantly higher than Kindle’s 650MB. This allows iBooks to contain embedded video and audio files. That means when a reader wants to access media in their eBook, they can tap or click their screen and the media will play automatically, even without an internet connection. Note that this does make large iBooks more difficult to manage via email or other online channels compared to their Kindle counterparts.


Barnes & Noble’s eBook reader is called the Nook. The Nook is a Kindle competitor and has many of the same features. The biggest difference is the eBook ecosystem supported by the different companies. For example, buying a Nook book allows you to lend it to other Nook owners. 

ePub (generic)

There are many more eBook platforms than the three listed above. Most, however, don’t require platform-specific file types. ePub files are the most generic and widely-used eBook format. An ePub file can be opened on any device or eReader software and will display well. Front Edge Publishing uses ePub files to publish on smaller eBook platforms, like Kobo. The Kobo eReader was originally designed to be a cheaper alternative to other devices. Kobo is an example of a smaller eBook platform that nonetheless has its own set of fans that appreciate being included in the full distribution of eBooks.

By producing ePub files for each book, Front Edge Publishing ensures every eBook can be distributed on as many platforms as there are interested readers. Furthermore, if a new platform becomes popular and requires a platform-specific file type, ePub files are the perfect place to start customizing for new format requirements.

Reading eBooks on a Computer

You don’t need an eReader to enjoy an eBook. There are several free and popular software applications that can be used to read on your desktop computer, laptop, tablet or mobile device. Calibre is a free software that reads ePub and other file types. offers a free Kindle app to recreate the Kindle experience on your computer or mobile device. Apple Books is free on the Apple store.

Front Edge Publishing authors can also make use of these free programs to review their eBook proofs if a device is not available.

Care to Read More?

This is part 6 of our Metadata 101 series

Part 1
How to create book metadata that will increase discoverability and enhance your marketing
Part 2
How to Write a Great Short and Long Description of your Book
Part 3
Determining binding, paper and color options for a printed book
Part 4
How to Request Endorsements, Forewords and Prefaces for New Books
Part 5
How do I find BISAC codes for a new book? 5 Tips for Success
Part 6
What are the different kinds of eBook formats? And, how do I make eBooks?
Part 7
Should we mention my dog? The Art of the Author Bio
Part 8
What should I call my book? The Art of Creating a Title and Subtitle
Part 9
Metadata by the numbers: What is an ISBN?

About Dmitri Barvinok

Director of Production Dmitri Barvinok works on the digital development, print layout and distribution of new books. He coordinates Front Edge editors and designers and works with the BookEdge software suite.

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