Guide to eBook Formats

EPUB

The ePub format is an open format designed by the Open eBook Forum and developed by the International Digital Publishing Forum. Based on XHTML and XML, it was made with the intention to be a both source file format and end user format. Examples of software that can open this format are EPUBReader Firefox add on, Adobe Digital Editions, and QuickReader. Meanwhile, devices that can open this file include the iPhone, iPod Touch, iPad, Sony Readers, Kobo Reader, and the Nook from Barnes & Noble.

AZW

This is an Amazon format used exclusively on the Amazon Kindle. It is basically a MOBI format that uses a high compression option. As Kindle apps have been released for devices other than the Kindle reader, AZW format files can also be opened on smartphones (iPhone, Android phones, and BlackBerry), computers (Mac and PCs), and tablets (iPad, Android tablets, and Windows 8 tablets).

PDF

The Portable Document Format was created by Adobe for its Acrobat products. This is a very popular e-book format since software support for this format exists for a lot of devices. Examples of PDF viewers are Adobe Reader, Foxit Reader, Nitro PDF reader, PDF-XChange Viewer, Xpdf, and a lot more. Most of these are freeware. One downside of this format is that content in PDF is usually scaled for A4 or letter size, which becomes unreadable when reduced in order to fit the small screens on smartphones.

MOBI

The e-book format used by the MobiPocket Reader, MOBI was originally made as a PalmDOC format’s extension. It can be opened using MobiPocket’s reading software, which can be installed on a lot of PDAs and smartphones. There are limitations of the MOBI format. For example, sizes of images cannot be scaled with the font size; tables display differently on different readers, especially if the table covers more than one screen; and there is an absence of support for nested tables. Third party readers such as Stanza, FBReader, Kindle for PC and Mac, and STDU Viewer can open MOBI files.