How to Convert EPUB to MOBI [But You Might Not Need To]

Update: Amazon has discontinued the use of the MOBI file, so there will likely not be a need to convert to MOBI again. Instead, we recommend this article about how to get your EPUB files on an Amazon Kindle.

You can convert EPUB to MOBI with a browser-based conversion tool (like CloudConvert), downloadable software (or Calibre), or a full eBook service that includes file format conversion (like BookBaby).

This might be surprising to a lot of people, but you don’t typically need to convert EPUBs to MOBIs as an author in 2022. This used to be a much bigger deal because Amazon didn’t automatically convert EPUBs to their own format, but now they do.

However, it is wise to upload your EPUB to Kindle Previewer to see exactly how your eBook will look on an Amazon Kindle device before publishing on Amazon’s marketplace.

In this article, you will learn:
  1. Do you need to convert EPUB to MOBI?
  2. What is better than MOBI files for Amazon Kindles?
  3. What are the best tools to convert EPUB to MOBI

What is the difference between EPUB and MOBI?

Before we get into how to convert from EPUB to MOBI, let's first take a look at their differences so as to better understand when someone should do this:

  • An EPUB file (“electronic publishing”) is a free, open standard, and open-source file format based on HTML, XML, and CSS. It is the universal gold standard for eBook publishing. Unlike MOBIs, EPUB eBooks can be read by most devices, including Android mobile phones and Sony eReaders. The EPUB was developed by the International Digital Publishing Forum (IDPF) in 2007, replacing the OEBPS.
  • A MOBI file is a file extension designed for eBooks, but mostly on Amazon Kindle devices. MOBI eBooks use XHTML and can include Javascript. MOBIs have a much larger file size than EPUBs. The name comes from the company Mobipocket Reader, which Amazon owned from 2005-2016, at which point Amazon shut it down. MOBI has spawned multiple descendants and variants, like the AZW3 and KFX.

Years ago, you had to convert to MOBI to publish your eBook on Amazon’s Kindle Direct Publishing marketplace. Nowadays, Amazon accepts lots of file formats, like EPUB, PDF, and DOC/DOCX. Then, Amazon’s built-in uploader converts it to MOBI.

(Actually, Amazon converts these file formats into a variant of the MOBI format, but trust me, it’s complicated. And not that important for you to know.)

You no longer need to convert EPUB to MOBI files to publish on Amazon’s marketplace. Amazon does that automatically for most file formats, including EPUB. MOBI is no longer at the top of their list of recommended file formats. MOBI’s predecessor, the PRC file, is no longer supported.

However, readers still need to convert EPUB files to MOBI (AZW3), PDF, or TXT if they want to read their already-purchased or downloaded EPUBs on a Kindle device.

For example, if a reader purchases an eBook from Apple Books, it probably came formatted as an EPUB file. But you can’t open that EPUB file on your Kindle. This is because your Kindle (an Amazon product) can only natively read a MOBI file (AZW3).

Can I convert EPUB to Kindle format? Yes, you can easily convert EPUB to Kindle format. Amazon Kindle devices can natively read MOBI, AZW3, KFX, and KPF files. Authors don’t really need to convert EPUB to MOBI, but may find it helpful to convert EPUB to KPF before publishing on KDP.

Book Formatting Files: EPUB, MOBI/AZW3, PDF, and More

Why would you need to convert your EPUB to an Amazon-friendly file format? You may need to convert your EPUB to an Amazon-friendly file format like MOBI (AZW3) to preview how your eBook will look on a Kindle device. You do not need to convert to MOBI to publish on Amazon’s vast eBook marketplace.

Ensuring you have properly converted file formats is important, but not as complicated as it used to be. Most book retailers accept EPUB, PDF, and other formats.

Amazon’s marketplace — Kindle Direct Publishing — accepts many file formats, including EPUBs, then converts them to the latest version of MOBI (AZW3). Though their conversion software is pretty good, it’s safer to convert your EPUB to an Amazon-friendly file before publishing.

This is where people used to say, “So, you need to convert your eBook to MOBI.” However, MOBI is actually quite outdated. AZW, AZW3, KFX, and KPF are the modern descendants of the MOBI.

Before uploading your mind-blowing manuscript to Kindle Direct Publishing, I recommend using Kindle Create or at least Kindle Previewer to convert your eBook into a KPF, which allows you to see exactly what a Kindle user will see when they read your book.

Kindle Create allows you to edit the look and feel of your eBook. Kindle Previewer simply allows you to review how your eBook looks on a Kindle device, but as a desktop application.

Why is Amazon’s marketplace so important? Because it commands over 80% market share over eBook sales. Consult the stunning chart below:

ebook sales by marketplace

Converting your EPUB files to MOBI (AZW3) files (or the newer KPF) is paramount to the launch of your eBook. Accessing Amazon’s vast eBook marketplace means ensuring your eBook looks professional and perfect as can be.

Best Tools to Convert EPUB to MOBI

There are some amazing all-in-one services that can convert EPUB to MOBI without sending your precious manuscript to a potentially unsecured server.

Calibre is a secure, reliable, and time-tested piece of software that is my pick for best file converter. But there are other eBook services with different advantages.Is it easy to convert EPUB to MOBI? Yes, it is easy to convert EPUB to MOBI. You can use a free online tool like Convertio or CloudConvert. If you’re worried about online security, you may want to download a secure, reliable conversion software like Calibre.


Calibre is one of the oldest available eBook managers out there. It is reliable, secure, and great for your file conversion needs.

Don’t let its age fool you. It is one of the best tools for any eBook reader out there. It has a lot of handy features to improve your quality of life when it comes to publishing your eBook.

Calibre’s ability to convert file formats back and forth is bar none. And it’s free!

Although Calibre has grown to include many tools and management systems for eBooks, the company actually started out converting eBook formats. And they haven’t stopped. Calibre can perform just about any file format conversion you can think of.

The one biggest setback to Calibre is its ability to handle DRM (Digital Rights Management). In order to handle Kindle and other DRM protected files, you must first download an additional plugin.

Calibre is compatible with several operating systems, including:

  • Windows
  • Windows 64-bit
  • Mac OS
  • Linux
  • Android OS
  • iOS (Apple mobile devices)
Calibre ebook management

Now that we know about Calibre is and what it can do, let's go ahead and check out how to use it in order to convert EPUB to MOBI using Calibre. As you'll see, Calibre can be used to effectively convert the file type. However, it's not as intuitive.


Zamzar is great for converting just one book at a time. Zamzar has a free, browser-based conversion tool that converts a lot of different files formats into other formats — not just eBook formats, either.

Simply upload your eBook to Zamzar, and they will almost instantaneously let you download your newly formatted file.

This is not a destructive process. You retain the original copy when using this type of service.

Zamzar Online File Conversion

As you can see, ZamZar is an effective option for converting your book from EPUB to MOBI. In order to get a better feel with its capabilities, here is a full video that will show you how to effectively use ZamZar to do this trick with your books:


CloudConvert is a free, browser-based conversion service that doesn’t require you to download any software.

It is fast, easy, and completely free. Although these browser-based conversion tools delete your file from their servers within 24 hours (you still retain your own copy), some people do worry about the security of their files for that 24 hour period.

But your files should be safe using these tools.

CloudConvert allows you to upload files from:

  • Your computer
  • A specific URL
  • Google Drive
  • Dropbox
  • OneDrive

EPUB to MOBI Converter (Reedsy)

Reedsy's EPUB to MOBI Converter is just that: a simple tool that can turn any of your EPUB files into a MOBI file.

Simply upload (or drag and drop) your EPUB file, enter your email address, and receive a MOBI file as soon as the conversion is done — a few seconds.

This EPUB to MOBI converter uses the conversion technology of the Reedsy Book Editor, Reedsy's free formatting tool for authors with export options to EPUB, MOBI, and print-ready PDF.

Any eBook Converter

Yes, this conversion tool is called Any eBook Converter. And it’s a really great service.

From its sleek design to its simplicity of use, this tool is the most user-friendly conversion tool out there.

While it doesn’t have the immense file format capabilities as Calibre, it handles all of the major file platforms utilized by eReaders.

And the best part is you don’t even have to add books to your library. The program automatically scans your computer for any Kindle, Adobe Digital, or Nook eBook file, then uploads them to your library. From there, you can edit all aspects of the book’s metadata and convert as needed.

However, Any eBook Converter only works on Windows, not Macs.

It costs $29.95 for the full software, but the trial version is free and unlimited. You can only convert 1 eBook at a time with the trial version, but that’s good enough for most authors.

This is a great choice for those looking for a simpler alternative to Calibre.

any ebook converter

Professional Services To Help You Convert EPUB to MOBI

You may be uncomfortable handling the proper conversion of your eBook, scared you may mess your manuscript up in the process.

It may be better for you to leave it to professionals to convert your EPUB into a more-than-presentable MOBI/AZW3.

Each professional service has its own perks. Some even put your eBook through helpful quality checks to make sure your beautiful EPUB didn’t become an unsightly MOBI.

Here are 3 top-notch file converter services you can use:

  1. BookBaby is the absolute best conversion service out there, in my humble opinion. It's more of a full eBook makeover than a simple conversion. They conduct a 100-point Quality Control inspection on your source file. And in case you have any questions, you can always contact their free customer service.
  2. Bookmobile is primarily a book printing service, but they also provide excellent conversion services for eBooks. Bookmobile provides comprehensive quality checks on your eBook, everything from link functionality, metadata, images, and much more! They also provide line by line proofreading for an additional charge.
  3. eBooks2go can provide you with either a reflowable or fixed EPUB or MOBI. This ensures that no matter what device your book is read on, it will look polished and professional. They also offer enhanced features, like highlighted read-aloud text and embedded videos/animations.

Format Beautiful Professional Books

Easy to use, and and full of amazing features, you can quickly turn your book into a professional book.

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How to Send a MOBI to Kindle Devices

  1. First, convert your file (like an EPUB) to MOBI. Kindles cannot read EPUB files natively.
  2. Then, connect your Kindle to another device, such as your desktop computer.
  3. You should be able to drag and drop files over your network or wired connection. 
  4. You can also use Amazon’s Send-to-Kindle email address to email the file to your personal Kindle email address. There are a few steps to this process, so try following Amazon’s how-to list to transfer an eBook to your Kindle this way.

Sideloading is when you transfer a file from one device to another, kind of like uploading and downloading.

To sideload various files on and off your Kindle device, you can connect your Kindle to your computer via wired connection or WIFi, then copy/paste or drag and drop. You may send the file via email as well, although it may take a little work to set up your email on your Kindle.

Kindle devices can’t read EPUBs natively. This is the main reason you would ever have to convert an EPUB to a MOBI file. Readers and authors alike will need to convert previously-purchased EPUBs into MOBIs if you need to send it to and read it on a Kindle device.

Step-by-Step: How to Convert EPUB to MOBI in Kindle Previewer

Here are simple step-by-step instructions on how to convert EPUB to MOBI in Kindle Previewer:

Download, install, and open Kindle Previewer. This is what it should look like when you open it:

Kindle previewer

You can either click on the blue button, “Open Book”, or drag and drop an EPUB file into the dotted line rectangle.

Kindle previewer epub to mobi

It’s as easy as that to convert EPUB to MOBI in Kindle Previewer.

While we’re here, the second screenshot is a great example of why you should at least review your eBook in Kindle Previewer before publishing it on Amazon’s marketplace. This is definitely not the title page you want readers to see as soon as they open up your eBook — but this author was able to correct it with a few clicks.

How to Use Kindle Previewer to Review Your eBook

It’s important you know how to use Kindle Previewer to review your eBook before it goes on the Amazon marketplace, Kindle Direct Publishing (KDP).

When I downloaded and installed Kindle Previewer, its size was just over 1 GB. Make sure you’ve got open space on your hard drive before you begin.

Kindle Previewer recommends only uploading EPUBs or DOCXs into Kindle Previewer. If you try to upload a MOBI then an AZW3 to Kindle Previewer, error messages will pop up.

You can click “Open Book” or drag and drop to upload your eBook to the application. If it’s an EPUB (or various other non-MOBI file formats), Kindle Previewer will automatically convert it.

If you don’t like how your book looks in Kindle Previewer, you have 2 main options:

  1. You can edit your EPUB or DOCX or whatever your raw eBook is formatted as. Edit it then view it in Kindle Previewer again, to see if your changes in the raw format changed your eBook as viewed on a Kindle.
  2. Open your DOCX eBook in Kindle Create. There, you can edit your manuscript as if it were on a Kindle device. Kindle Create is a little clunky, but it’s the best tool to edit your eBook as if viewing it on a Kindle. (As far as I can tell, you have to upload a DOC/DOCX file into Kindle Create. Converting EPUB to DOCX is as easy as the Google search, “convert epub to docx”. Or you can use secure desktop software, like Calibre.)

You can also use Kindle Create to edit the look and feel of your eBook. I recommend you take the time to familiarize yourself with the impressive functionality of Kindle Create to maximize how great your book looks in the biggest eBook marketplace on the planet: Amazon’s KDP.

What is the difference between Kindle Previewer and Kindle Create? Kindle Previewer lets you review your eBook as if it were on a Kindle device. Kindle Create lets you edit how your eBook looks on a Kindle device.

Which file format conversion tool is right for you?

A fully-equipped desktop platform like Calibre may be your best bet if you have lofty plans for your eBooks. Calibre is free, easy to use, and great for converting file formats, including EPUB to MOBI.

But if you’re a casual reader or hobbyist writer, a smaller platform might be better. There are plenty of free online conversion tools available with only a quick Google search. Google has done a good job of only displaying safe, legitimate conversion websites that are still working in 2021.

If you're looking for a professional conversion service, I'd go with BookBaby. BookBaby offers a full quality check for your eBook file format, as well as customer service included at no extra cost with your purchase.

The real trick is to balance what you need with the overall ability of the software. This is one of those areas you may want to keep simple. Remember, less is more.


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3 thoughts on “How to Convert EPUB to MOBI [But You Might Not Need To]

  1. Dean Whitlock

    I have a book with a special font in it that is absolutely required. These are special characters (runes) that appear inline with the body text at many places. The font will have to be embedded in epub or mobi files. I can produce an epub using Pages, but not a a mobi, so I’ll need a converter. (The normal body text font is not critical. In the print edition, I use a version of Baskerville, but any of the standard ePub reader fonts will work.)

    Can any of these converters handle embedded fonts, including the inline style changes required for characters that are scattered within paragraphs?


    1. Dave Chesson

      Oh, nice question. I honestly don’t know. But if you find out, please let me know here.

  2. Lorilyn Roberts

    If you have a Mac, use Vellum. Best on the market for books. Calibre has issues.I won’t go into them here, but Vellum is in a league of its own. Here is the link for more information. It is $250 for one-time purchase, and worth every penny. And I have no affiliation with the company, just sharing my experience of almost ten years.

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