EPUB vs MOBI vs PDF: Which E-Book Formats Should You Use?

EPUB vs MOBI vs PDF Which E-Book Formats Should You Use

Created your classic book and ready to share it with digital platforms? Well, there can still be a challenge waiting for you. With each marketplace (Amazon, Google Play, Apple Books, etc.) supporting different eBook formats, which one is best for you to reach a wider audience using minimum effort? Not to worry, here is an in-depth comparison of the most popular eBook formats – EPUB vs MOBI vs PDF.

What is the Importance of Choosing the Right eBook Format?

eBook readers allow you to increase the font size, change the background color, and do other things to make reading on your device more comfortable. However, problems can arise when the formatting of your ebook format is of poor quality. For example:

  • The lines are jagged.
  • Page breaks are messed up.
  • The text is reflowing oddly.
  • And other similar issues.

This can often happen when an ebook is not correctly converted from its original format into the ebook format you’re trying to read it on. For this reason, it’s essential to ensure you use suitable ebook formats according to the device.

In this article, Alpha eBook – the eBook conversion specialist, will discuss the three most popular ebook formats: EPUB, MOBI, and PDF, to help you decide which format is best for you.

Understanding The Top 3 Primary eBook Formats

EPUB, MOBI, and PDF are today’s primary eBook formats. And you should specifically use a format that matches the marketplace where you want to publish your eBook. For example, Amazon specifically uses the AZW3 format for their marketplace and all Kindle devices. However, it is not required to convert your book to AZW3 from your side – we will discuss that later in the article.

Which Marketplace Accepts Which eBook Format?

Amazon and Kindle eReaders previously accepted MOBI formats for their marketplace. Currently, it accepts EPUB formats and converts them to their own AZW3 file.

There are some marketplaces that accept different eBook formats, while most of them accept EPUB formats.

You can publish EPUB and PDFs to Apple Books and Google Play.

Here is a tabular representation to make it simple.

Marketplace EPUB MOBI/AZW3 PDF
Google Play
Apple Books
Barnes & Noble (NOOK)

As you can see, some platforms allow you to use MOBI and PDF formats; however, an ideal choice is to use EPUB formats, as they can be accepted everywhere. Still, we will dig a bit deeper into all these formats.

What is EPUB?

What is EPUB

EPUB is a format designed specifically for reflowable content, meaning that the text automatically adjusts to fit the screen size of your device. It is also designed to work with various eBook readers, such as the Amazon Kindle, Nook, iPad, and Sony Reader, making it one of the most versatile and user-friendly eBook formats.

Also, DRM-enabled EPUB files can prevent the distribution of harmful files. Because of this, large publishing houses use our EPUB conversion services as a de facto industry standard whenever they want to release a book on any website. In general, we can say that EPUB files are typically the best option.


  • They are compatible with almost all e-readers, smartphones, and tablets.
  • As a reflowable format, it gets adjusted as per the screen size making it easier to read.
  • They support audio, video, multimedia, and other interactive elements which helps enhance the reading experience.
  • EPUB formats are simple and easy to create.


  • It cannot support complex layouts affecting the readability of certain types of books.
  • Doesn’t properly support a fixed layout, so it can be difficult to convert your book that requires a precise layout and design.

When Should I Use EPUB Format?

Primarily, you should always prefer using EPUB formats as they are widely accepted by all the marketplaces and platforms. Amazon also accepts this format; however, as it immediately converts it to AZW3 format, it might be possible that this conversion affects your formatting. Generally, this doesn’t happen, but it is advisable to check and review your book’s formatting when you publish it to KDP.

What is MOBI/AZW3?

What is MOBI AZW3

MOBI is the native format for Amazon Kindle devices. The format became popular because Amazon used it exclusively for eBooks sold on their website. Therefore, if you wanted to publish an eBook on Amazon, you needed Kindle eBook formatting to ensure your book appears correctly on all Kindle devices.

MOBI features advanced navigation controls, file searching, decompression, and dictionaries. The format also allows the user to add notes, highlights, and bookmarks.

However, as Amazon discontinued Mobipocket in 2016, Mobi was also discontinued by the end of 2022, with EPUB replacing its functions.

So the MOBI format is a past now and even Amazon recommends using EPUB format. Still, some authors might want to use MOBI if they are comfortable with the older format. However, it’s better to use EPUB.


  • They are compatible with Amazon, Kindle Devices, and some other platforms that support the format.
  • They support complex layouts making it an ideal choice for certain types of books.
  • It comes with an in-built dictionary allowing users to understand words without leaving the book.
  • Can be easily published on Amazon Kindle Direct Publishing, simplifying the process for Authors and Publishers.


  • The format is not widely compatible with all the marketplace, e-readers, and devices.
  • Doesn’t support audio, video, and other multimedia.
  • Supports limited font styles.

When Should I Use MOBI Format?

It is not suggested to use the MOBI format as Amazon even doesn’t support the MOBI format and you can get all the functionality with the EPUB format.

What is a PDF?

What is a PDF

PDF is a format developed by Adobe in the early 1990s. It was designed as a way to view documents electronically, regardless of the software or operating system they were created on. It is a digital printout of a document that works well on large screens but can be challenging to read on smaller screens such as cell phones and eReaders.

One reason PDF has remained popular is that it can preserve the original formatting of a document even if it has a lot of data, images, and graphic-based media. PDF is also a good format for sharing documents because people can open and view PDFs even if they don’t have the software used to create them.


  • They are compatible with most devices, including smartphones, tablets, and desktops.
  • Being a fixed layout format, it doesn’t change its design no matter which device you use.
  • You can secure it using a password limiting unauthorized access and sharing.


  • They cannot be edited, once you converted your file to PDF, you cannot edit it unless you have the source file.
  • PDFs can be large, making it difficult to share and publish with platforms, and also require more storage than other formats.
  • Difficult to convert to other formats, especially if it has complex formatting.

When Should I Use PDF Format?

You can use PDF when you need your book to be in a certain format. For example, a graphical format that doesn’t need to be changed. They are also the most universal and widely used format; still, there are certain disadvantages to using it.

They are not reflowable, which is not suitable for any device other than a printer. As they cannot be resized, it makes them difficult to read on different devices like smartphones, tablets, and desktops.

Epub vs Mobi vs PDF: The Difference Between Each eBook Format

Now that we’ve gone over the basics of each format let’s take a more in-depth look at the key differences between EPUB, MOBI, and PDF.

Platforms Supported

PDF and EPUB are compatible with most eBook readers and devices such as Apple’s iPad, the Amazon Kindle, Barnes & Noble’s Nook, Sony Reader, BeBook, Bookeen Cybook Gen3, and many more. MOBI, on the other hand, is the native format for Amazon Kindle devices but can also be read on other eBook readers with the appropriate software installed, such as MobiPocket Reader or FBReader.


Both EPUB and MOBI files are designed for reflowable content, meaning that the layout can adjust to fit the screen size of your device. This makes both formats user-friendly and easy to read, even on small screens like cell phones.

PDFs, however, are static layouts that remain one size regardless of the device it is being viewed on. This can make PDFs challenging to read on small screens and often require zooming in and scrolling around to view the entire document.

Interactive Elements

EPUB files can support a variety of interactive elements such as audio, video, animations, and more. MOBI files can also support some interactive features but to a lesser extent than EPUB. PDFs, on the other hand, are not designed to help interactive elements; as such, any interactivity will have to be added by the PDF creator.

File Size

EPUB files are typically smaller than PDFs and MOBI files, making them ideal for devices with limited storage space.

PDFs can vary depending on the data they contain but are often larger than EPUB and MOBI files.

MOBI files are typically larger than EPUB files but smaller than PDFs.


MOBI has DRM protection built-in, meaning that you can add security to your eBook files to prevent unauthorized copying or sharing.

EPUB, being an open format, does not have DRM protection built in, but third-party software programs can add DRM to EPUB files.

PDFs are equipped with Adobe’s digital security. You can add password protection to PDF files to prevent unauthorized access.


EPUB is the most widely supported eBook format and is, therefore, the best format to use if you want your eBook to be compatible with the broadest range of devices and software.

With special software installed, MOBI files can be read on a few other eBook readers besides Kindle.

PDFs can be read on almost any device but may not be as user-friendly as EPUB or MOBI files.

Let us compare these formats with each other:


While MOBI would be a choice for you when you wanted to use Amazon as your marketplace a few years back; however, as MOBI is discontinued and not being accepted by Amazon itself, there is no reason for not using EPUB as your primary format.


PDF is and was never better than MOBI unless and until you want your book to be printed. If you want to upload and share your eBook to digital platforms and marketplaces, PDF is not the right choice.


EPUB is always a better choice for e-reading and distribution. Being reflowable, it is a suitable choice for a better user experience. However, if you merely want to use your eBook for the printer, then PDF would be a better choice.

Which Format Should You Use for Your eBook?

Choosing a clear winner between EPUB, MOBI, and PDF as the best eBook format can be tricky. Each format has advantages and disadvantages that make it better or worse for specific purposes. However, we suggest that most authors primarily go with EPUB formats.

Alpha eBook conversion specialists recommend the following eBook formats for specific purposes:

If you are a writer looking to self-publish your work, our MOBI conversion service can be best for you, as Amazon’s Kindle Direct Publishing (KDP) platform is one of the most popular ways to self-publish eBooks.

We recommend our PDF conversion services for business professionals who want to distribute reports, white papers, or other corporate documents. PDF is a widely used format for business documents and can be easily shared and printed.

However, we recommend our EPUB conversion service if you want your content to be read on the broadest range of devices and software. EPUB is the most widely supported eBook format and can be read on almost any device or software.

No matter your specific needs, our ebook format service can provide you with the best solution for converting your content into any desired format.

Contact us today to learn more about our services or get started on your project.

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Frequently Asked Questions about eBook Formats

Which eBook format is best to read on smartphones?

EPUB format can be considered the best for reading an eBook on smartphones. Almost all smartphones support this format and you can read an EPUB file easily on them. Smartphones also support PDF and MOBI formats; however, they do not look as good as EPUBs on small screens.

How can I convert my book to an eBook?

You can contact our experts for the best eBook conversion service with affordable cost and timely delivery. We convert any file formats including Word, HTML, InDesign, etc. into popular eBook formats such as EPUB, MOBI, AZW3, and PDF.

Which is the best format for reading an eBook?

EPUB is the best format for downloading and reading an eBook as most devices and e-readers support this format.

Which is the best format to print an eBook?

PDF is the best format if you need to print your book, because of the fixed layout, it doesn’t get changed no matter what screen and device you use. You can print your book and get the original format and quality.

Which is the best eBook format for Kindle?

Kindle e-readers use their own Kindle File Format – AZW3 (an updated version of MOBI). However, while uploading an eBook to Amazon marketplace or Kindle e-reader, you can use formats like EPUB, doc, or docx files.

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