It is supported by fourth-generation Kindle devices running firmware version 4.1.0 or later and the Kindle Fire device. In addition, it has several other formatting options and is used by Amazon for all new Amazon eBooks.
It supports HTML5 and CSS3, which were not supported through the standard AZW format. Application/pdf, application/x-pdf, application/x-bzpdf, application/x-gzpdfĪZW3 - Kindle Format 8 (KF8) is Amazon's newer version of AZW.