Amazon is going to be supporting the EPUB format later this year. Users will be able to use Send to Kindle to upload EPUB books directly to their e-reader. Amazon is working on the system integration right now and should be rolled out globally in August. We will be able to send EPUB books using our Send to Kindle email address. The company will also be adding EPUB support to the free Kindle app for iOS and Android devices and the Send to Kindle desktop app for PC and Mac.
EPUB became the official standard for digital book formats in 2007 and received major revisions ever since. EPUB is the most widely supported vendor-independent XML-based (as opposed to PDF) e-book format; that is, it is supported by almost all hardware readers. Amazon is basically the only company that uses their own book formats, while Apple Books, Barnes and Noble, Kobo, Google Books, Scribd, Overdrive and virtually everyone else uses and supports EPUB. It is the widely used format out there and if you want to download a book online, it will always be available as an EPUB file.