PDFs and common accessibility misconceptions

29 May 2019

Portable document format files, or PDFs, are as much a part of our lives as the internet itself. Sometimes they cop a bit of flak for being inaccessible, when in reality, if they are tagged correctly they can meet Web Content Accessibility Guidelines (WCAG).

So what exactly is a PDF and how do you make yours accessible to people with disability, especially those who are blind or have low vision and use screen readers?

What is a PDF?

PDFs are mainly used to distribute read-only documents and are commonly used for documents like user manuals, eBooks, application forms and scanned documents. They often contain text, images, embedded fonts, hyperlinks, video, interactive buttons, forms and more.

Created by Adobe in the 1990s, the PDF set out to achieve two things.

  1. Providing a document that can be opened on any operating system, without needing to have the app used to create them—all you need is a PDF reader; and
  2. Wherever you open a PDF, the layout of the document should look the same.

Are PDFs accessible?

The short answer is yes, they can be WCAG compliant, provided they are tagged correctly.

Adobe Acrobat Pro DC can ‘auto-tag’ PDFs, but that doesn’t mean it’s done correctly.

Auto taggers do not take context into account when creating tags and will not be able to provide key accessibility functions such as alternate text, recognising decorative images or recognising the use of particular headings and styles.

Problems with auto-tagged PDFs

There can be a number of issues with relying on auto-tagging. Three of the most common issues are:

  1. Decorative images being tagged when they don’t need to be. Sometimes these tagged decorative images are the top of the tag tree.
  2. Bullet points being tagged as individual paragraphs for each line. This means someone using a screen reader will not get information about how many items are in a list or be able to navigate it properly – as well as having the bullet announced as part of the content.
  3. Headings being identified as ‘figures’ or images, instead of having their appropriate heading level. This will mean these headings are likely to not be read at all, and the document loses the heading structure to give context to the rest of the information.

This screenshot below highlights the three common auto-tagged mistakes when compared to an accessible one.

Screen shot of Adobe Acrobat DC accessibility checker

Making a PDF accessible

A reasonably simple document does not take long to make WCAG compliant - accessible, but errors like those listed above can make the information very difficult to understand and does not allow someone using a screen reader to receive the same meaning as a sighted user.

Participating in a training program such as Advanced Creating Accessible Documents: Adobe PDF, will teach you the skills to become an accessible PDF hero; ensuring your digital documents are accessible to everyone, including people with disability.

As a first step, for those with a bit of training in making documents accessible, here is the accessible version of same flyer featured above that can be used as a template to check against when making your own documents accessible.

There are also organisations such as Tagged PDF who are able to provide a quick and free document check service that will identify accessibility issues in documents.

For more information on training offered by Vision Australia’s Digital Access consultancy visit the Vision Australia website.