.EPUB File Extension

Open eBook File

Developer IDPF
3.5  |  690 Votes
Category eBook Files
Format Zip

What is an EPUB file?

An EPUB file is a digital eBook saved in the EPUB format, an open XML-based format for digital books and publications. It is a standard digital publication format publishers and consumers utilize to store the text of the book, chapter links, cover art, images, and more eBook elements. Supporting software programs and hardware devices, called e-readers, can view EPUB files.

More Information
Screenshot of a .epub file in Apple Books 5
EPUB file open in Apple Books 5

The EPUB format is based on three open standards maintained by the International Digital Publishing Forum (IDPF). The standards are:

  1. The Open Publication Structure (OPS), which defines the content markup
  2. The Open Packaging Format (OPF), which describes the eBook structure
  3. The Open Container Format (OCF), which packages all the eBook files together in a compressed format

NOTE: Many commercial eBooks include digital rights management (DRM) protection. Only authorized devices can view the eBook if the eBook includes DRM information.

How to open an EPUB file

You can open an EPUB file and read the book it contains using the following ereader programs:

If you want to edit the book an EPUB file contains, you can do so using an eBook editor, such as Calibre.

How to convert an EPUB file

Calibre can convert EPUB files to various file types, including the following formats:

  • .AZW3 - Amazon KF8 eBook
  • .MOBI - Mobipocket eBook
  • .FB2 - FictionBook 2.0 File
  • .LIT - eBook File
  • .LRF - Sony Portable Reader File
  • .PDF - Portable Document Format
  • .DOCX - Microsoft Word Document
  • .RTF - Rich Text Format
  • .TXT - Plain Text
Open and view .EPUB files with File Viewer Plus.Free Download

Programs that open or reference EPUB files

Updated June 16, 2022

Verified by FileInfo.com

The FileInfo.com team has independently researched the Open eBook file format and Mac, Windows, Linux, Android, and iOS apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

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