PDFs are one of the quickest, easiest and most effective ways to share complex information – but is this popular format always accessible to all?

The PDF, or Portable Document Format, has been an industry standard for sharing information since the 1990s. Supported across almost all platforms and easy to use, it has become the standard format for so many functions from teaching and e-learning, to creative and commercial communication. In fact, wherever you need file sharing flexibility with the reassurance of almost universal access, you’ll probably find a PDF!

However, this universal acceptance assumes equal ability. For many visually impaired people or those with access issues, the PDF format can be restrictive.

In this article we’re examining the PDF in a little more detail, looking at some of the challenges people with visual impairment face, and what we can do to make sure PDFs are accessible to as many people as possible.

PDFs have come a long way

PDFs were developed by Adobe Systems in 1993 and quickly became the go-to format for publishing and reading digital documents. By 2008 PDFs had become the ISO standard.

The PDF/UA (Universal Accessibility) is a revision of the original PDF standard. It defines the guidelines for making PDF documents more accessible and it too became an ISO Standard in July 2012.

PDF/UA is referenced by the latest Web Content Accessibility Guidelines (WCAG) 2.2

What sort of accessibility challenges do people have with PDFs?

Visually impaired people, and anyone else with accessibility issues, typically need to either enhance PDF documents for better readability, or use screen reading technologies - such as text-to-speech systems.

This raises some challenges:

• Some text is not actually ‘text’: Sometimes PDFs contain scanned images of text, or text within images, which makes them inaccessible to text-to-speech reading systems.
• The structure: PDFs that lack intuitive structure - clear, appropriate headings and paragraphs - make it hard to find what you are looking for and make it difficult for screen readers to navigate.
• Missing or inaccurate alternative text: If you include images and graphics in a document, and you don’t add descriptive alternative texts, they cannot be interpreted by screen readers.
• The layout can be too complex: Complex layouts with multiple columns, tables, or overlapping elements might look great, but can return confused results.
• The colour contrast is low: If the colour contrast between text and background is too low, it can make it difficult for people with impaired vision to see text clearly, and be missed by screen readers.

Accessibility: It pays to start early

There are some things you can do right from the start to make sure any document is as accessible as possible for everyone.

• Use clear and simple language: Always avoid jargon and complex sentence structures, use clear headings and subheadings.
• Apply consistent formatting: Maintain consistent formatting throughout the document where you can, including font size, font type, and colour.
• Adopt a logical reading order: Ensure that the reading order of the content is logical and easy to follow.
• Add alternative text for images: Provide descriptive alternative text for all images to help screen readers understand the visual content.
• Suitable colour contrast: Always use sufficient colour contrast between text and background to improve readability.

So, what is the PDF/UA Standard?

Following PDF/UA standards provides firm guidelines for creating accessible PDFs.

PDF/UA includes several features in support of accessibility. The core of this is the ability to determine the logical order of content in a PDF document independently of the content’s appearance or layout by using tags - hence the term tagged PDF.

Tagging a PDF involves adding structural elements to the document, such as hierarchical headings, paragraphs, and tables. This helps screen readers understand the document's organization. It allows assistive technology like screen readers and web browsers to read a PDF out loud, reflow it for a small screen and facilitate users who rely on keyboard control.

While all PDFs can faithfully render printed material on digital devices as well as print media, PDF/UA ensures that documents are fully accessible in either format.

It’s also good to use the following techniques:

• Optical Character Recognition (OCR): You should ensure that the PDF is OCR-processed to make the text searchable and readable by screen readers.
• Table Structure: If you use tables to organise information, they should be clear and use a properly defined structure, including headers and row/column relationships.
• Hyperlinks: Apply clear and descriptive hyperlink text and avoid ambiguous phrases like "Click here."

How can you tell if a PDF is accessible enough?

There are built-in accessibility checkers in many PDF editing tools. These can quickly and resolve identify potential issues.

You could also use third-party accessibility testing tools to perform a comprehensive accessibility audit as well as manually reviewing your PDF to check if it’s easy to navigate and understand. You can even test it with different screen reader technologies to identify any issues that automated tools may miss.

If possible - and if the project is a more substantial one - you may be able to ask people with specific disabilities to get involved in the testing process so you can get their feedback.

You should always keep up-to-date with the latest accessibility standards and guidelines to ensure your PDFs meet the highest standards.

How Spiral can help

Through many years working with accessibility for both big and small companies and organisations, the team here at Spiral have found that the best way to approach accessibility is to examine the user journey before we start. We use a digital first approach, where the digital version is designed to meet all requirements, then any print variants are built to work in tandem with those digital assets.

Working with an agency like Spiral can make all the difference. We can ensure your PDFs cater to the diverse needs of your audience whilst meeting all your technical and inclusivity requirements so that everything you do works for everyone.