What is an EPUB 3?

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What is an EPUB?

EPUB is a dynamic, widely supported format for eBooks.  The EPUB format gained popularity over the years by offering a more flexible reading experience than other, more static formats like PDF.  That’s because EPUBs are actually made up of the same code that is used to create websites.  EPUB files are also compatible with the vast majority of eReaders.  For these reasons and others, EPUBs are favored by digital booksellers and publishers alike.   

What is an EPUB 3 and what makes it different? 

EPUB 3, the third major iteration of the popular EPUB eBook format, introduces a wide variety of improvements over EPUB 2.  One of the biggest changes is the shift to HTML5, which provides the format with a much clearer structure and order than EPUB 2.  EPUB 3 also supports additional media, such as video and audio.  You can even add behaviors and interactivity with Javascript.  These additions are particularly useful in educational settings.  Digital textbooks and learning materials can present information in multiple ways and even offer learning assessments–or quizzes–right in the text. 

Arguably one of the most important areas of improvement for EPUB 3 is accessibility.   Because EPUBs are written in the same way as websites, they can be held to the same accessibility standards as websites.  Standards like WCAG 2.0, for example.  These standards offer content creators and developers a helpful set of guidelines to ensure that their content is available to anyone—including users who utilize assistive devices or software. 

HTML5 is particularly important when it comes to accessibility.  Its improved structure makes content much easier to navigate using assistive devices and software.  Another important addition is the use of MathML (Mathematical Markup Language).  Previously, math equations had been represented by static images alone.  MathML instead represents them with XML text.  This allows these equations to be read by assistive devices or scaled, making them available and accessible to all users.  

Why should you use it? 

Accessibility benefits aside, EPUB 3 is a very attractive choice for anybody looking to release a book digitally.  It is compatible with almost all eReaders and supported by most eBook sellers and marketplaces. Simply put, EPUB3 is the best available option for publishers and creators looking to provide an intuitive reading experience to as wide a market as possible. 

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