PDF, EPUB or MOBI – Which E-book Format Should You Choose?

E-books are gaining more and more fans, and their popularity increases every time a new e-book bookstore appears on the market. No wonder – most bookstores willingly offer the opportunity to purchase e-books, while others sell books only in this format.

Cheap e-books cost even several times less than paper versions, and additionally, a whole lot of them can fit in one small reader, which saves space on book shelves. Less paper consumption is important for the good of the planet, which also affects the growing sales of e-books. 

For anyone who wants to try reading e-books, it’s time to make a decision – which e-book format to choose? Are they any different? Can every e-book format be read on every device?

Available e-book formats

The choice of a specific format is important from the point of view of the reader we have. We have three basic e-book formats to choose from.

  • PDFe-books

Downloadable e-books in the correct format are certainly the oldest available publication format and until recently were used quite often. However, a large number of disadvantages and limitations mean that this format is increasingly abandoned, and PDF e-books are no longer found so often in online bookstores.

The biggest disadvantages of the PDF format are the inability to scale the font, as well as the rigid page division, which makes it impossible to freely adjust the file to the screen size. 

How secure is the PDF format in terms of data protection?

The PDF format is very secure in terms of data protection and is often used to store sensitive information. These files are typically encrypted and password protected, making your data more secure than other file formats. Additionally, PDF files are almost unbreakable, which means they are more secure than other file formats.

Is the PDF format compatible with all operating systems?

Yes, the format is compatible with most available operating systems, including Windows, Mac OS and Linux. All viewer programs are free and easy to use.

PDF viewer program

Viewing files is an important element of everyday work on a desktop or laptop computer – regardless of whether they involve professional or private tasks. Some people do not need advanced tools with lots of functions to simply open documents saved in this popular format. 

Although we usually strive to ensure that the applications we download have as many functions as possible and are multitasking, we should not forget that a rich arsenal of tools, especially in the case of PDF files, is also associated with a higher price of the entire product.

Therefore, it is not always worth investing in a program that we do not really need if all our work with documents in PDF format is limited only to displaying and viewing e-books. Most applications that only allow you to open files with this file format for free, but if you need to modify them, there are some the best PDF editing programs.

  • EPUB

EPUB stands for Electronic Publication or e-publishing files. EPUB format e-books are by far the most common. It is supported by the vast majority of factors – in fact, the only devices that are not compatiblewith this format are Kindle-branded devices. This official, open e-publication format was prepared by the International Digital Forum and has many practical possibilities, and can even benefit small businesses with time saving solutions. First of all, it is the most “plastic” of the formats.


The EPUB format is also readable on portable devices other than e-book readers. You can easily find and download applications that will make this format readable on both Android smartphones and iOS products, making these the best e-books for iPad.

  • MOBI

MOBI e-books play only on Amazon devices, making it a typical Kindle e-book. Kindle was one of the first readers, and the MOBI format was created as an extension created just for it and it does not read any other file format. 

However, you can use the application integrated with Kindle to play e-books in the MOBI format on your computer or smartphone, and some non-Amazon readers also offer this option. Just like on other devices, e-books on Kindle allow you to adjust the font size, take notes and bookmarks. To convert your PDF into an EPUB or MOBI file, see this free ebook converter.

How to choose the right e-book format?

There are several aspects you need to keep in mind before choosing the right e-book format. Issues along the way to selection and publication can be resolved by keeping some basic aspects in mind. You should consider the following points:

  • Who is your target audience? The people you write or post are just children, adults or parents. This must be kept in his consideration. For example a NFL fan may want to read about the Superbowl 2024 so choosing formats that support the content is imperative.
  • What content do you choose for your book? Deals with the design or pattern of a book. If the book includes images and graphics or only contains plain text, which e-book format will be good.
  • The place– Where you are going to publish your book should be considered an important thing.

To sum up

As we can see, the question about the differences between PDF, EPUB and MOBI extensions does not matter much – these formats are similar to each other, and most books can be purchased in both extensions. 

The problem with choosing a reader comes down to choosing a specific brand of device and then the best model for you.

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Michael P
Los Angeles based finance writer covering everything from crypto to the markets.
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