AZW3 supports a subset of HTML5 and CSS3 features, while acting as a container for a backwards-compatible MOBI content document. In late 2011, the Kindle Fire introduced 'Kindle Format 8' (KF8), also known as AZW3 file format. Kindle devices can also display some generic document formats such as plain text (TXT) and Portable Document Format (PDF) files however, reflowing is not supported for these file types.

Software such as the free and open source Calibre, Amazon's KindleGen, and the email based Send-to-Kindle service are available to convert e-books into supported Kindle file formats. AZW files debuted with the first Amazon Kindle in 2007. Similar to EPUB, Amazon's file formats are intended for reflowable, richly formatted e-book content and support DRM restrictions, but unlike EPUB, they are proprietary formats.

When uploaded via the Send to Kindle service Kindles now support the EPUB file format used by many other e-book readers. Kindle devices and apps are designed to use Amazon's e-book formats: AZW that is based on Mobipocket in fourth generation and later Kindles, AZW3, also called KF8 and in seventh generation and later Kindles, KFX. azw3 extension, and version 10 introduced a new typesetting and layout engine featuring hyphens, kerning, & ligatures and have the. azw version 8 (KF8) introduced HTML5 & CSS3 features and have the. E-book files in the Kindle File Format originally had the filename extension. Kindle File Format is a proprietary e-book file format created by that can be downloaded and read on devices like smartphones, tablets, computers, or e-readers that have Amazon's Kindle app.

Kindle format mobi