What is the Difference between ePUB & ePUB3?

What is the Difference between ePUB and ePUB3?

What is the Difference between ePUB and ePUB3?

If you’re an aspiring author, you’ve probably heard of ePUB and ePUB3. But what’s the difference between the two? In this post, we’ll explain the critical differences between these two formats so that you can choose the right one for your needs.

ePUB and ePUB3 are eBook formats, adhering to specific standards set out by the International Digital Publishing Forum. While they are very similar in appearance, there are significant differences between how these specifications handle various aspects of eBook creation that can significantly affect what you see when viewing an eBook.

What is an ePUB Format?

ePUB is a digital file format used to create and distribute eBooks. It is a standard format that most eBook reading devices support.

The ePUB file format is best suitable for electronic publications with reflowable text. It is more like a  marked-up document structure with associated images and illustrations.

The ePUB format is accepted and distributed by most major eBook stores and platforms, including Google, Apple’s iBooks, Barnes & Noble’s NOOK, and KOBO.

What is an ePUB 3 File?

ePUB 3 is the latest version of ePUB, and it is an HTML5 standard-based file format. It allows the ePUB 3 files to contain videos, audio, and interactive multimedia elements. In a nutshell, it is an enhanced and more versatile version of the ePUB format. It allows for more multimedia content, interactivity, and animation.

ePUB 3 format makes it perfect for digital textbooks, cookbooks, travel guides, and other types of interactive content. If you’re thinking about self-publishing an eBook or want to make your current eBook more engaging, you should consider using the ePUB 3 format.

ePUB 3 file is best suited for a fixed-layout eBook, which heavily depends on images and videos.

What is the Difference between ePUB and ePUB3?

The Features of both ePUB & ePUB 3 Versions

  • One of the main benefits of the ePUB files for readers is that it allows a book’s text to automatically adjust or “reflow” for different screen sizes, such as those for smartphones, netbooks, and eReader devices. 
  • The ePUB version allows publishers to control document presentation through style sheets. ePUB 3 also provides audio, including synchronization of text and audio and text-to-speech synthesis.

Differences between ePUB & ePUB 3 Versions



ePUB 3

ePUB 2 is an older format that was adopted by many organizations as their standard eBook format. ePUB 2 offers minimal controls for formatting text and images for its users.ePUB 3 offers greater flexibility in layout and typography, allowing publishers to create more sophisticated designs and page layouts.
ePUB 2 readers are not compatible with multimedia elements like videos,animations etc. Therefore, users need to confine themselves to reading non-interactive eBooks.ePUB 3 supports the embedding of audio, video, and media overlays. Since ePUB3 is based on the HTML5 format, it incorporates all of HTML5’s capabilities for rich media integration and interactivity.
ePUB 2 does not support non-Latin script languages (Arabic, Chinese, Korean, etc.).ePUB 3 supports a wide range of languages. Books written in various languages are supported, as ePUB 3 has the capability to handle the flow of the text in RTL or LTR.
Only JPG and PNG images are supported in ePUB 2.ePUB 3 supports MathML and SVG to represent vector graphics inline within content. Pages will be lighter, thus reducing load time when we use the SVG element to draw shapes.
ePUB 2 does not support features related to accessibility and interactivity.ePUB 3 incorporates various accessibility features such as support for alt text descriptions for images, enhanced navigation for readers with disabilities, and text-to-speech capabilities.
ePUB 2 does not support fixed layout formats or read-aloud functionality.”In ePUB 3, fixed layout is supported, and it provides various features for interactivity, including pop-up notes, hyperlinks, and interactive quizzes.


  • ePUB 2 does not support scripts and interactivity features. ePUB 3 version supports scripted content, i.e., interactivity, using JavaScript language.
  • ePUB 2 does not support the text-to-speech facility. ePUB 3 provides text-to-speech facility (Pronunciation Lexicons (PLS), Inline SSML Phonemes, CSS speech  features). It also enables the usage of SMIL (Synchronized Multimedia Integration Language) for representation of synchronized text and audio.

The ePUB 3 is the latest version of ePUB which includes many new features:

  • Better Accessibility

It also improves on previous versions by supporting a wider variety of fonts and text styles, allowing for more control over how your content looks when read. 

  • Global Language Support 

Offers compatibility for multiple languages. Books written in different languages (including Hebrew, Arabic, etc.) enable both left-to-right and right-to-left writing. 

  • MathML Support

There is a direct embedding of MathML supported in ePub3, which makes it a perfect choice for science, math, and engineering textbooks.

Suppose you are unsure which format to use to reach the widest audience possible with your eBook or digital publication. In that case, it may be worth looking into what each has to offer before making a decision – both formats have their advantages!

Related Blogs you Might be Interested in