Epub files are used for creating digital publications and e-books. The epub file format is the common standard and can be opened with many programs. Only Amazon Kindle doesn’t support epub files.
What is an epub file?
The epub file is an open standard used primarily for creating e-books. Epub stands for “electronic publication”. The epub file format is the successor to the older Open eBook and has been under development since 2007 as part of the International Digital Publishing Forum (IDPF). The file extension is .epub. Meanwhile, the XML-based format is the standard for digital publications and e-books and is compatible with numerous programs.
An epub file combines text content and its structure, covers, images, and possibly sounds, as well as metadata such as a table of contents. Open web standards such as CSS, XHTML, and XML are used for this purpose. In addition to the actual book data, the epub file can also contain digital rights management (DRM) mechanisms. The target audience for the epub file type is primarily publishers and consumers who create or read e-books.
The epub file format is based on three open standards, all managed by the IDPF:
- OPS: The Open Publication Structure for formatting content.
- OPF: The Open Packaging Format, which defines the structure.
- OCF: the Open Container Format, which allows all necessary data to be stored in a ZIP archive with the .epub extension.
Advantages of the epub file format
The biggest advantages of the epub file format are its versatility and dynamic presentation. It’s possible to open epub files with many different programs and devices. That’s because the files adapt to the corresponding device. For example, while pdf files can be difficult to read, especially on smaller screens like smartphones or tablets, epub files always automatically adapt to the exact format. Since the file works with flowing text, this will automatically adapt to the respective device. It’s also possible to switch from portrait to landscape format.
Disadvantages of the epub file format
Even though the epub file format is widely used, it’s not completely error-free. Especially for publications that have many large graphics or tables, the traditional PDF format has its advantages. However, these files are also more likely to be opened on devices with a larger screen.
Despite its widespread use, there is one successful e-book reader, Kindle, that doesn’t support epub files. Since Amazon uses its own proprietary formats, epub files must first be converted at great expense before they can be read on a Kindle device. While this is still possible in principle for works without copy protection, this does not apply to encrypted publications. Thus, there is no legal way to read them on a Kindle.
How to open an epub file
However, apart from Kindle, there is free and paid software that can open epub files for all major operating systems.
- Android: Android users can open epub files with Cool Reader or Google Play Books, for example.
- iOS: For iPhone, there is Apple iBooks, among others, to view epub files.
- Desktop: There are also numerous programs available to open epub files on desktop. A popular free option is Calibre, an e-book management tool that runs on Linux, Mac, and PC. There’s also FBReader, Okular, and Sigil, or the previously mentioned Cool Reader.
How to open an epub file online
If you don’t currently have an e-book reader handy, you can also open epub files online. MagicScroll is one of the web apps that work on any popular browser. This program lets you read e-books on your desktop online. E-book providers like tolino also have their own web apps that let you open epub files online. In addition, there are add-ons and tools for e-books for some browsers. Chrome, for example, offers the free browser app Simple EPUB Reader. EPUBReader for Firefox is also free. Both tools let you read e-books from your desktop or online.