What are the most common e-book formats?
Kindle
Kindle comes first, because it is the 500 lb canary of e-readers. Not because the Kindle is so great (although we think it is) but because Amazon is the biggest bookstore in the world and that’s where loads and loads of people go to buy books. And Amazon only sells ebooks for the Kindle.
The availability of Kindle apps for other devices (PC, Mac, iPhone, iPod Touch, iPad, Android) allows people to read Kindle books even if they don’t own a Kindle.
The Kindle’s native file format is proprietary (.azw). Kindles can also read Mobipocket files (.prc or .mobi) and text files (.txt). Some file formats (Word, HTML, RTF, JPEG, GIF, PNG, and BMP) can be converted for the Kindle by emailing them to Amazon. Amazon will convert them and send them to the Kindle. (The Kindle DX is a larger device. It can read pdf files without conversion.)
ePub
ePub, an ebook standard created by the International Digital Publishing Forum (IDPF), is probably the next most important format.
ePub files (.epub) can be read on the Apple iPad, the Barnes & Noble Nook, Sony Reader, IREX eReader, COOL-ER Reader, Plastic Logic, BeBook, jetBook, Hanlin eReader, and devices using Android.
PDF files (.pdf) are formatted files. They display pages that look exactly as they were designed to look.
This works very well for books, because book designers go to a great deal of trouble to create an aesthetically pleasing design, but the text is not “flowable,” which limits its usefulness for ebook readers that require flowable text. E-readers with larger screens, like the Kindle DX and the Apple iPad, can display PDF files reasonably well, and there are apps that will make them “flowable.”
LIT
LIT files are read by the Microsoft Reader, a free downloadable program for reading ebooks on a
computer, Pocket PC, and some other Windows Mobile Devices.
PDB
PDB files are readable by anything that uses the Palm operating system (PalmOS).
Other ebook formats
There are many other e-book formats, as you can tell from Wikipedia’s Comparison of ebook formats [1], but the ones listed here are probably more than enough. Kindle will get your e-book listed on Amazon.com.
ePub will get you listed almost everywhere else.