PDF Accessibility

Oct 19, 2019

Get questions answered about PDF accessibility. Learn the the what, when, why, and how.

What is a PDF?

A Portable Document Format. (PDF) is a file format developed by Adobe Systems Inc. as a way to publish documents electronically, with good formatting for printing, and document security (documents are generally read only). Originally it was in an image format. It was conceived as a way to make Adobe's Postscript printer language portable, and it mostly developed along the lines of press printing document production. Its prevalence can be attributed to the ease with which one can create PDF files.

PDF has accessibility and usability issues. One of the main problems with PDF concerns content elements which have not received appropriate treatment to support accessibility such as using structural formatting for headings, etc. or text equivalents for images. Compared to HTML, PDF is slow and cumbersome. Many applications can save to formats other than their native file format, such as HTML, so this option when available is preferable to PDF, even when it needs to be cleaned up for the web.

Why make a PDF accessible?

  • It is the right thing to do. Goal 2 of the University of Minnesota Duluth's Strategic Plan is to, "Advance equity, diversity, inclusiveness, and social justice within the campus community."
  • It is the law.
  • It is university policy.
  • It is good strategy. Accessibility makes content more usable for everyone.
  • It is a good way to avoid problems. Inaccessible content is a liability and can lead to complaints, intervention by regulatory agencies, bad publicity, expensive site redesigns, and lawsuits. Disability rights organizations have filed lawsuits against universities and colleges.

When should a web page or document be used instead of a PDF?

In the majority of cases an HTML based document is a better and simpler choice than a PDF. Whenever possible, publish as an webpage or an accessible document. It's the best way to reach as many people as possible. As David MacDonald, WCAG Working Group Invited Expert has stated in PDF vs HTML: Which is the Best Route to Reach WCAG 2.0 ask yourself, "Is HTML the best route to reach destination WCAG 2.0 AA? Today, the answer for many organizations is 'yes', even for content that is currently only available in PDF."

In PDF Issues & Recommendations Penn State states,

we continue to recommend to avoid or minimize using PDF files as a sole source of online information…

North Carolina State recently held The Great PDF Purge to cull PDFs from their university.

As GOV.UK states in content should be published in HTML and not PDF, the problems with PDFs include:

  • They do not change size to fit the browser
  • They're not designed for reading on screens
  • It's harder to track their use
  • They cause difficulties for navigation and orientation
  • They can be hard for some users to access
  • They're less likely to be kept up to date
  • They're hard to reuse

What other options do I have instead of using a PDF?

As Penn State advises, Convert PDF Files to Other Formats.

What makes a PDF accessible?

It is tagged accurately, according to standards, including but not limited to:

  • It has a title information in its metadata
  • It has a language defined (for screen readers and other tools)
  • The document has a logical reading structure defined, including headings.
  • Decorative and descriptive images have descriptions
  • Information is not conveyed by color alone.
  • All text (with the exception of logos) has a contrast ratio of 4.5:1 or greater no matter the size.
  • All link text be understood out of context.
  • All table header cells contain text.
  • Tab order of form fields is logical.
  • Check the U.S. Department of Health & Human Services' Required Fixes for PDF Files for more requirements.

What should I do before attempting to remediate my inaccessible PDFs?

  • Cull all PDFs that are outdated or redundant from the site, and
  • Identify all PDFs can be converted to web pages or web forms.

How do I fix my remaining PDFs to make them accessible?

Create and Verify PDF Accessibility with Acrobat Pro.
Adobe Acrobat Pro will help you ensure your that your PDFs are tagged accurately, according to standards.
Attend the PDF Hackathon for Accessibility
In-person help will be available on Friday, October 25, from 8:00 to 4:00 in Kirby Plaza 175.

How do I learn more?

Resources are available.