How to choose the best file format for digital publishing


In the publishing world, it’s impossible to talk about content without talking about formats.

From blog posts, newspaper articles, and magazine spreads, to journal articles, textbook chapters, or social media posts, each piece of content can have many different formats. 

For example, think about the most recent book you read (or listened to). Was it a physical book, a digital version, or an audiobook? The ways we consume content ultimately dictate the formats in which the content is published.

Content in the digital age

The Internet and digital publishing have caused a massive shift in the way content is consumed. More than 64% of the world’s population is now online (about 5.16 billion people), and mobile devices account for over half of total internet traffic worldwide.

Thanks to this monumental shift, digital publishing is now a $40 billion market that is projected to grow to over $67 billion by 2027. Suffice to say, digital formats are important for the future of publishing.

However, despite the dominance of digital formats, print is far from dead. Over 788 million printed books were sold in the US in 2022—the second-highest sales mark for printed books in the 21st century! That number was surpassed only by printed book sales in 2021, so there is clearly still high demand for printed publications.

Choosing a format

With so many ways to publish and consume content, it can be difficult to choose the best format to publish in. To figure out what file formats might be best for your content, it’s helpful to consider these questions:

1) Who is your target audience?

Knowing who is consuming your content and what types of devices they are using will help you narrow down some of your publishing requirements.

2) What are your layout requirements?

Different types of content – like a magazine with lots of high-quality graphic spreads versus a novel that’s predominantly text – will have vastly different publishing requirements.

3) Do you need to consider accessibility?

Accessibility requirements will greatly influence the format you choose, so make sure to understand the relevant standards in your intended market. For example, Section 508 in the United States and the European Accessibility Act are both relatively strict standards, but they have different requirements.

Once you’ve answered these questions, you’ll have a better idea of what you need from your chosen file format. 

There are quite a few options to choose from. Below, we’ve broken down a few of the most popular publishing formats to help you to consider the best choice for your requirements, as well as the needs of your audience.

PDF: Providing graphic integrity across all devices

It took about a decade for the PDF (Portable Document Format) to truly become ubiquitous, but today it’s one of the most popular file formats in the world. Adobe estimated that there were more than 2.5 trillion PDFs in circulation across the globe in 2020, with about 303 billion PDFs opened using Adobe Document Cloud in that same year. (You can learn from the success story of the PDF format in a previous blog post!)

The PDF is now a broadly adopted format that can be created and opened by a myriad of different programs. The PDF also offers graphic integrity across systems, just as its makers back in the early 1990s intended. Whether you open a PDF on your computer or your phone, it’s going to look the same. 

These factors make the PDF a great choice for content that has a high visual component, especially if that content will be printed.

EPUB: The king of the eBooks

First developed in 2007, EPUB is an open standard format for electronic publication that is widely supported by a variety of devices. 

An EPUB is essentially a container that houses the same components that make up a basic website. Each EPUB contains multiple HTML files, Cascading Style Sheets (CSS), images, and additional data that controls how images display.

There are two types of EPUB: fixed and reflowable. The latter is the more widely adopted format, largely due to its responsive nature and accessibility features. For instance, a reflowable EPUB allows the reader to adjust the size of the text to suit their needs, and the text will adapt to the screen on which it’s being viewed.

EPUB is a great choice for text-heavy content, and content that needs to be accessible to people with visual impairments.

HTML: A living standard

Hypertext Markup Language (HTML) is a text-based programming language that is the bedrock of the internet. It can reference multimedia assets, CSS for layout, and JavaScript for interactivity. It has become so widely accepted that it’s now a Living Standard as agreed upon by W3C and WHATWG.

HTML is another great choice for digital publishing that many people favour. It’s especially good for content that needs to be both interactive and accessible while also maintaining strong visual appeal.

DAISY: Going beyond the audiobook

If accessibility is your primary concern, you may want to consider DAISY. Often described as “digital talking books,” DAISY stands for Digital Accessible Information System. 

DAISY books are played in special devices, and they go beyond a regular audiobook. DAISY users can run searches, add bookmarks, and adjust speaking speed without distorting audio, among other key features.

Single-Source Publishing: Could it be the right fit?

In today’s publishing landscape, the same content is commonly published in multiple formats. However, when introducing additional output requirements, it can be difficult to avoid increasing the amount of overall production work. Single-source publishing solves this problem.

Single-source publishing refers to the creation of a single source document, often referred to as the Single Source of Truth (SSoT), that can be converted into different file formats or languages with minimal effort. While this requires some upfront setup, it can provide immense time savings in the future.

This option is especially attractive for anyone publishing documents that: 

  • need to be iterated regularly
  • need to be produced in multiple languages
  • are consumed across devices and mediums 

Typefi enables incredibly fast single-source publishing using Adobe InDesign—get in touch with us to learn more about how we can help you.

Your best format depends on your requirements

The various file formats available to today’s publishers solve many different problems. If you can hone in on what your biggest challenges are, that can help inform which file format is best for your publishing needs.

If you find that there isn’t just one format that solves all your problems, then single-source publishing may be the best route. There are several well-established vendors out there today that can help you implement a system like this and save you countless hours of production.

With these things in mind, it’s time to analyse your content to determine the format that’s best for your publishing needs.

This article first appeared on the BookMachine Production & Operations blog.

Adobe and Document Cloud are either registered trademarks or trademarks of Adobe in the United States and/or other countries.

Jamie Brinkman

Jamie Brinkman

Senior Solutions Consultant | USA

Jamie has extensive experience in copy editing and is highly skilled in layout and design. After more than 10 years as a Senior Content Editor with a multinational mass media firm, she joined Typefi in 2014. In her current role as a Senior Solutions Consultant, Jamie works closely with clients to develop and implement automated publishing solutions, as well as provide ongoing training and support.