What is EPUB?

EPUB (short for electronic publication) is a free and open e-book standard by the International Digital Publishing Forum (IDPF). Files have the extension .epub. EPUB is designed for reflowable content, meaning that the text display can be optimized for the particular display device used by the reader of the EPUB-formatted book. The format is meant to function as a single format that publishers and conversion houses can use in-house, as well as for distribution and sale.


EPUB features

- Free and open
- Re-flowable (word wrap) and re-sizable text
- Inline raster and vector images
- Embedded metadata
- DRM support
- CSS styling
- Support for alternative renditions in the same file
- Use of out-of-line and inline XML islands to extend the functionality of EPUB

EPUB specifications

The EPUB file format comprises three specifications: Open Container Format (OCF), Open Publication Structure (OPS) and Open Packaging Format (OPF).

OCF is simply a zip-based standard used to encapsulate all of the pieces of a digital publication into a single file.

OPS describes the digital publication’s markup or content (words on the page).

OPF provides the navigation, packaging, metadata, and table of contents (how the pages relate to one another).

How to open EPUB file

First, you can check if there is a program in your computer can open the EPUB file by double clicking it, if not, you can download another application to open and view EPUB files. Currently, there are lots of ebook readers like B&N Nook and Sony Reader, and free utilities, such as Adobe Digital Editions (ADE), Calibre, Stanza DesktopMobipocket Reader DesktopOkular. If you want to view EPUB file on your smart phone, there are plently of iPhone and Android mobile apps you can make use of.

How to convert EPUB file

Another popular electronic file format is PDF which is used more in people's daily life and sometimes you may prefer PDF format for reading, then you can convert EPUB to PDF with a free PDF creator.

By the way, if you have PDF files and want to convert to EPUB, you can convert PDF to EPUB.