Best Formats for Publishing eBooks

Best Formats for Publishing eBooks

eBooks have had quite an interesting and revolutionary journey to date. It started with simple PDFs and evolved into interactive and ePub formats. Today, there are some amazing formats for publishing eBooks. As the demand for eBooks continues to grow, publishers have to make sure that they select the best formats to publish their eBooks.

According to market data, the eBooks market volume is expected to reach USD 15.69 billion by 2029 at a CAGR (2024-2029) of 1.44%. The number of readers in this market is expected to reach 1.2 billion by 2029.

By selecting the right formats, publishers can continue to enjoy a competitive edge in this evolving market. The advent of digital textbook platforms like KITABOO has made it easier for educational publishers to publish their eBooks in various formats.

This blog takes you through different types of formats for publishing eBooks to help you as an educational publisher, make a more informed decision.  

Table of Contents:

I. Significance of eBook Formats

II. Best Formats for Publishing eBooks

III. Conclusion

Significance of eBook Formats

eBook formats refer to the typical design processes that are applied to convert text and images of digital books into attractive layouts. Formatting is an essential step of the eBook publishing process.

Standard eBook formats offer features that enable readers to access and read digital books across multiple devices with different aspect ratios. They ensure convenience and compatibility for readers. Most importantly, eBook formats offer readers a seamless reading experience.

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Best Formats for Publishing eBooks

While publishing eBooks, publishers must consider these two perspectives:

As a Digital Publisher: Choose a format that helps balance productivity and cost-effectiveness at scale while retaining your competitive edge in the market.

End-Users: The end-users should find the content engaging, immersive, intriguing, interactive, and easy to read on all platforms, including mobiles, eReaders, tablets, laptops, etc.

To find a balance between these two needs, it is important to first understand the different types of formats that are available.

Let’s take a look at some of the best formats for publishing digital books:


The ePub (Electronic Publication) format is a widely used format for publishing eBooks. It was developed in 2007 by The International Digital Publishing Forum (IDPF).

This file format is known for its flexibility and compatibility across a wide range of devices, including smartphones, laptops, tablets, eReaders, etc. It supports multimedia features, such as hyperlinks, images, graphics, embedded audio, video, etc.

ePub can display both as reflowable or fixed layout content. It works great with the DRM protection systems to prevent unlawful eBook distribution.

PDF and Interactive PDF

Currently, all printed textbooks are converted into PDF format as a first step in their digital journey. While the PDF format is a cost-effective solution and compatible with almost all reading platforms, it fails to live up to the expectations of the digital generation, mainly because the content remains static.

Interactive PDF is an eBook format that combines the features of the traditional PDF file format with an interactive web experience. It incorporates various rich media content that readers can engage with. These include images, audio files, videos, links, GIFs, and more.

The Interactive PDF format is compatible across all kinds of devices and browsers. However, one drawback is that such PDFs are not reflowable.


This format is derived from a format called Mobipocket. It is the format Amazon uses for its Kindle eBooks and readers. However, it has limited compatibility with other eReaders.

The MOBI format supports complex layouts and is great for eBooks that require multiple columns. It supports bookmarking, frames, marking corrections, and adding notes. Font customization options are limited.


Microsoft Word’s proprietary format, DOCX, is the successor to DOC. It is easy to convert DOCX into different eBook formats. This open standard eBook format enables reflowing and editing of content for digital books.

DOCX supports certain interactive features, such as charts, images, audio files, video files, tables, and annotations. However, this format doesn’t support DRM protection.


RTF or the rich text format is another format developed by the Microsoft Corporation. It is primarily used for Word documents. RTF enables easy editing and formatting of content and retains special characters. It supports the reflowing of content and multimedia elements.

This format can be used for activating DRM protection measures and offers multi-device compatibility. Further, it allows the conversion of existing eBooks into other eBook formats. Thanks to its varied features, RTF has turned into a highly popular eBook format today.


ODT files belong to the Open Document Format (ODF), also known as OpenDocument. This format is used for LibreOffice and is very similar to Microsoft Word except that it is free and available for all platforms. LibreOffice files can be easily edited and written out to html, doc, docx, rtf, and other similar formats.


HTML5 has gained wide popularity across the globe since its inception in 2008. It’s a mobile-friendly format and supports the direct conversion of a textbook into this format.

This format is widely used in creating digital content because of its cross-platform compatibility and ability to support multimedia elements. It also allows hyperlinking of content to internal and external sources. HTML5 format is capable of functioning across devices such as eReader, tablets, smartphones, etc.


Of all the different formats available for publishing eBooks, the most popular format is the ePub3 format. The software provides global language support and can handle the flow of the text (RTL or LTR). It scores high in terms of offering readers greater access, functionality, and accessibility.

Besides, publishers can also gain reader feedback, and trace the number of times a particular eBook or paper is downloaded. In other words, they can analyze an end-user response to the content and accordingly enhance it for better productivity.

ePub3 content also offers business benefits in terms of cost savings, especially when you consider the overall process of content creation and distribution. With ePub3 content, publishers save in terms of publishing, binding, labeling, transport, and repair.

Overall, publishers can broaden their reach, increase reader engagement, lower costs, and achieve business acceleration by adopting ePub3.

If you want to reap the benefits of ePub3, you may want to consider KITABOO. It’s an award-winning ePub3-based digital publishing solution that has found favor with some of the biggest names in the world of publishing globally.

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Mike Harman

Mike Harman

Mike is the SVP Business Development at KITABOO. He has over 30 years experience in achieving consistent top-line revenue growth and building mutually beneficial relationships. More posts by Mike Harman