Suggestions for Kindle Format 8

Amazon's Kindle Format 8 is similar in many ways to the EPUB format, but it is not technically the same. There are two major schools of thought about how to handle these differences: 1) create one EPUB file and give it to every retailer, including Amazon, without a lot of changes or Kindle-specific coding; and 2) create a separate Kindle file from separate source code, usually based on the EPUB source code.

Which option you choose will probably depend on the book you are converting, the standards of your publishing house, and the time you have available. For more complex titles, it can be very helpful to consider creating separate files for each retailer, with tweaks that will make the files work better in each ecosystem. However, if you want to create only one file, that is also an acceptable solution in many cases.

Single-source file preparation

Let's start out with the single-file solution and talk about the differences between EPUB and KF8. As we mentioned above, KF8 is very similar to EPUB. They actually come from the same core Open eBook standard (what was essentially EPUB 1). KF8 files include the same core source files as EPUB: the OPF file and the NCX or HTML Nav doc. KF8 also supports both XHTML 1.1 (used in EPUB 2) and HTML5 (used in EPUB 3), so there are no major differences between KF8 and both reflowable versions of EPUB in use today. (Note, however, that KF8 fixed layout is significantly different than EPUB fixed layout, and usually requires extensive changes to work properly.)

To that end, you do not have to worry about changing those core files in major ways to ensure that they are understood by Amazon's systems. The main differences will be in what formatting works, how HTML and CSS are supported, and other differences that are more stylistic than they are structural.

Note that in addition to actual formatting or support differences, there are some requirements and best practices that are specific to the Kindle platform, as with other retailers. These issues are included in the list below, and will also be flagged in the Amazon section of FlightDeck's Retailer Acceptance Grid for your EPUB file.

Here are the major differences between KF8 and EPUB, and the issues to watch out for when creating a single-source EPUB files:

Converting EPUB to KF8

If you decide that you want to create a specific file for Amazon so that the differences do not affect the file you give to other retailers, you can provide them with either an EPUB file or a KF8 file. If you decide to give them an EPUB, just be sure you have converted it with KindleGen and tested it on the Kindle devices before delivering it. The basic process includes the following steps:

  1. Unzip the EPUB, and pull out the OEBPS folder and related files.
  2. Remove the Cover HTML file, as well as all references to it in the OPF and NCX/HTML Nav.
  3. Move anchors in front of formatting tags if desired.
  4. Add backwards compatibility to complex formatting if desired.
  5. Fix or change any of the other items listed above.
  6. Rebuild your EPUB file, and run it through KindleGen. Load it on Kindle devices to ensure the conversion works properly and the formatting is working.
  7. Deliver either the EPUB source or the .mobi output to Amazon.
  8. Back to Handbook