Katherine Wang / August 4, 2020

An Introduction to Popular E-book File Formats

Some of the popular file formats include Adobe PDF, Microsoft LIT, Amazon AZW, Mobipocket PRC, PDB, etc. Some popular PC content formats, such as HTML, TXT, and DOC, may also compete as e-book formats. In this article, let’s have a look at some of these popular file formats and their software readers.

1. Amazon AZW

With the production of Amazon Kindle, Amazon created also a file format that Kindle recognizes, called AZW. With its own DRM (Digital Rights Management) structure, AZW format protects the e-book publishers and authors from possible piracy. Kindle recognizes only this format, and other formats should be translated into AZW before they can be read through Kindle device. In order to do this, Kindle provides a free email conversion system, which helps you download the books in any other format to Kindle through an email. AZW is loosely based on Mobipocket’s popular MOBI file format.

Kindle DX � a large screen device that is actually 1.5 times larger than the regular Kindle display � offers native PDF support and according to the article “Which eBook Reader is the Most Suitable for Me?” has been specially designed for reading electronic versions of newspapers, magazines, and formatted books (Digital Book Readers).

2. Adobe PDF

Adobe’s PDF (Portable Document Format) is not just an e-book format, but also a popular PC file format. First created in 1993, it became popular long before the e-book revolution started. It was created for storing and transferring portable, printable documents. Adobe’s own PostScript format forms the basis of PDF documents.

PDF documents support compression, password protection, and are viewable in virtually all platforms (hence the name ‘portable document format’). It is estimated that more than 250 million PDF documents are in existence on the Web. Adobe’s software applications, Acrobat and Acrobat Reader were used to create and read PDF files, but in 2008, PDF was released as an open standard, and now there are several applications available to read and edit PDF documents. This has enhanced PDF’s popularity in the e-book arena.

3. Microsoft LIT

With severe competition from Adobe and other popular e-book formats, Microsoft also came up with their own proprietary e-book format, LIT. Files with extension ‘LIT’ are accessed and read by the Microsoft Reader, available as a free download from Microsoft website. The application is available only for Windows operating system.

Microsoft Reader can be used for reading e-books on portable devices with the help of ClearType technology, which renders improved text on those devices. It was first introduced in 2000.

LIT format also supports DRM (Digital Rights Management), protecting e-book author and publisher rights. You should activate the Microsoft Reader once installed in your PC, tablet PC, or pocket PC, through Reader activation website. You can purchase the e-books in LIT format from Microsoft Reader website as well.

4. Palm E-book Format (PDB)

Palm Database format (PDB) is a proprietary format used in Palm PDAs. It can however be accessed on Windows or other type of OS with the help of specialized software.

Palm’s own eReader is a free program for reading PDB files. This reader is available for a number of devices and operating systems�BlackBerry, iPhone, Macintosh, PalmOS, PocketPC, Symbian, Windows Mobile Smartphone, etc.

You can purchase and download e-books from eReader website, and read them through your device. There are also a number of classics in public domain available in PDB format for free. The purchased books are encrypted for safety.

5. Mobipocket PRC or MOBI

Mobipocket is a French software company that creates the Mobipocket Reader, which can be used to read e-books on your PDA or smart phone. The reader’s native format is PRC. The PRC format and Reader are supported under BlackBerry, Franklin eBookMan, PalmOS, Symbian, PocketPC, Windows Mobile Smartphone.

Mobipocket Reader gives you an e-book library for storing and managing all your e-books. You can edit the metadata associated with the e-books, such as author information, title, publisher, and rate e-books. You can transfer e-books to any of your PDA devices from your PC through a USB connection. You can also incorporate notes and annotations on your e-books and highlight any term. Also, the reader allows you to look up the definitions of any term easily through available dictionaries, which include Longman, Merriam Webster, Oxford, and others.


Those are the most popular of e-book document formats. There are also less popular formats associated with specific reading devices. However, since most readers recognize almost all formats, it is easy for users to read e-books in any reading device. The conversion and publishing of e-books on any of these formats is also easy with the help of specialized software.