EPUB

Electronic Publication (EPUB)

Filename extension	.epub
Internet media type	application/epub+zip
Magic number	PK\x03\x04 (Zip)
Developed by	International Digital Publishing Forum (IDPF)
Initial release	September 2007; 16 years ago (2007 -09)
Latest release	3.3 May 25, 2023; 11 months ago (2023-05-25)[1]
Type of format	e-book file format
Contained by	OEBPS Container Format (OCF; Zip)
Extended from	Open eBook, XHTML, CSS, DTBook
Standard	ISO/IEC TS 30135
Open format?	Yes
Website	w3.org/epub3

EPUB is an e-book file format that uses the ".epub" file extension. The term is short for electronic publication and is sometimes stylized as ePub. EPUB is supported by many e-readers, and compatible software is available for most smartphones, tablets, and computers. EPUB is a technical standard published by the International Digital Publishing Forum (IDPF). It became an official standard of the IDPF in September 2007, superseding the older Open eBook (OEB) standard.^[2]

The Book Industry Study Group endorses EPUB 3 as the format of choice for packaging content and has stated that the global book publishing industry should rally around a single standard.^[3] The EPUB format is implemented as an archive file consisting of XHTML files carrying the content, along with images and other supporting files. EPUB is the most widely supported vendor-independent XML-based e-book format; that is, it is supported by almost all hardware readers.^[4]