EPUB files use the .epub extension. EPUB stands for electronic publication. EPUB files are e-book files based on open standards. Therefore EPUBs are layout agnostic – formatting isn’t affected by screen size.
You can view EPUB files on screens as small as 3.5 inches. Many modern devices have built-in EPUB support. There are also e-reader apps for desktop and mobile. These allow you to read EPUB files.
You can open an EPUB file as a Zip archive. To do this, rename the file extension to .zip. You can then extract the contents to view or modify them. However, editing may corrupt the eBook.
There are ways to convert EPUB files to other formats. Calibre can convert to various file types. This includes PDF, MOBI and more.
EPUB gradually became a popular eBook format with major publishers. Nowadays, many e-readers and apps support it. Even Mac OS has built-in EPUB support. EPUB uses ZIP compression to store contents in an XML based open format. Metadata is also stored.
Adobe Digital Editions
Calibre
Apple Books