KF8 (Kindle Format 8) is a file format developed by Amazon for use in Kindle eBooks. It is the successor to the older MOBI format and offers enhanced features, including support for HTML5 and CSS3, which allows for more complex layouts, embedded fonts, and improved image handling. KF8 files can contain fixed-layout elements, making them suitable for children's books, comics, and textbooks where precise formatting is crucial. The format also supports features like pop-up footnotes, scalable vector graphics (SVGs), and better metadata handling. KF8 is primarily used on Amazon's Kindle devices and Kindle apps, but it can also be read by some other e-reader software. The format is designed to provide a richer and more visually appealing reading experience compared to its predecessor, MOBI, and allows publishers to create more sophisticated and interactive eBooks. While KF8 offers significant improvements, it is often bundled with a MOBI version within the same file to ensure compatibility with older Kindle devices that do not support KF8.