Fixed layout ebooks

A fixed layout ebook (FXL) is an exact visual replica of your print book but in the digital space, meaning that it has the same page layout without changes to text size, font, colors, etc. Fixed layout ebooks can also include various interactive capabilities, such as hyperlinks, table of contents, and accessibility features for print-disabled readers. Fixed layout ebooks are typically recommended for children’s books, coffee table books, or highly designed books that are very complex and won’t translate well to reflowable ebook formats. 

Fixed layout ebook formats: 

• FXL epub3 - (.epub) This is the industry standard and accepted by most distributors. 
• kf8 - (.mobi) This is Amazon’s proprietary format, as they do not support FXL epub format. There are two kinds of kf8s:  children’s and comics.
• interactive PDF - (.pdf) This was the old industry standard, and most distributors have replaced it with FXL epub3. But a few smaller and more niche distributors still use PDF format.

Reflowable ebooks

A reflowable ebook is an interpretation of your print book in the digital space, meaning that it does not have the same exact page layout, but it retains the fonts, design, and the overall flavor of the print book. Reflowable ebooks “reflow” based on user settings to control text size, font, margins, line height, colors, and more. Reflowable ebooks also have many more accessibility capabilities that allow print-disabled users to perceive, navigate, and enjoy your book’s content. Reflowable ebooks are typically recommended for any text-heavy books, like novels, reference books, textbooks, and most cookbooks. 

Reflowable ebook formats:

• epub3 - (.epub) This is the industry standard and accepted by most distributors, including Amazon
• epub2 - (.epub) This was the old industry standard, that was superseded by the reflowable epub3 standard. Distributors continue to sell epub2, but the format is over a decade out of date and not very user friendly. Anyone who has a reflowable epub2 file should consider getting it converted to reflowable epub3 format to increase usability by newer technology and accessibility features.
• mobi - (.mobi) This nearly-deprecated proprietary Amazon format was replaced by reflowable epub3 in June 2022 for any newly uploaded ebooks. But Amazon continues to support any mobi ebooks that were uploaded prior to this date. Anyone who has a reflowable mobi should consider getting it converted to reflowable epub format, as total deprecation of the reflowable mobi format is anticipated.