eBook Formats

eBooks are available in various formats. The most common are:

  • ePub2
  • ePub3
  • .prc (formerly .azw or .mobi)
  • KF8
  • Fixed Format

The most universal eBook file format is EPUB (short for ‘electronic publication’). Almost all reading devices support (are compatible with) EPUB. Before you get too excited, you should know that Amazon’s market leading Kindle eReaders do not support EPUB. To read an eBook on a Kindle, it has to be in .mobi/.prc format.

Firsty will convert your files into EPUB. We use EPUB because it is the most widely supported format and because it is recommended by the International Digital Publishing Forum (IDPF)*.  For a small extra fee, we will also convert your EPUB file into a .mobi/.prc file for Kindle.

 *The IDPF is the trade and standards organisation for the digital publishing industry and it is committed to developing, publishing, and maintaining common standards (e.g. EPUB) relating to electronic publications and promoting the successful adoption of these specifications.  Source: www.idpf.org/about-us

Whereas EPUB and .mobi/.prc eBooks are reflowable, eBooks in Fixed Format are not.  As the name suggests the layout of the content of each page (text, artwork, etc.) is fixed, just like it is in a print book.  If you have highly illustrated titles, coffee table books or complex page layouts where the page layout and design are integral parts of the reading experience a fixed format may be the best format for you. By converting to Fixed Format, however, you will limit your audience and routes to market and as yet there is no universal fixed format that will work across platforms/devices.

Think too about who your readers are and on what devices they are likely to want to read your eBook? If you are an education, academic or STM publisher you might find that the majority of your readers will still consume your eBooks on a PC or Mac. Does this have an impact on your conversion priorities? If content is to be used in a classroom then how important is a mobile friendly format?  Do you need to convert to ePUB, is HTML5 without the EPUB wrapper a better option? Have you considered web or native apps as an alternative? There are lots more questions some of which you may already have answered, but I guess our advice is not to be too hasty or blinkered.  Just because everyone else is doing it doesn’t mean they are doing it right!

Health Warning: It’s possible to sell PDF and standard EPUB or .mobi file formats and audio books direct from your own website, but it is not possible to sell enhanced or fixed format ebooks direct. Sorry, but at present there isn’t a simple work-around for this.