Over-reliance on automated PDF accessibility checkers

The PDF accessibility checker built into Acrobat Professional (version 11 onwards) is a very useful tool.


It absolutely, categorically, does NOT test the accessibility of a PDF and give you a yes or no answer (and neither does anything else calling itself a PDF accessibility checker).

I have written about this previously elsewhere but am prompted to do so again after hearing twice in a week of web managers of large corporates commissioning external graphic designers to create “accessible” PDFs. In both cases the designers were simply instructed that their documents must pass the Adobe PDF accessibility checker, and nothing more.

So what’s the problem?

To be blunt, if this is your benchmark, the chances that you will be producing accessible PDFs are practically zero.

The benefits of automated checking

The Acrobat PDF accessibility checker has many excellent features that can help greatly in identifying and fixing potential problems.

The screenshot below shows the checker’s results panel highlighting a number of potential problems in a document. In many cases you can simply right-click/crtl-click an item to get a menu that includes the magic word “Fix”. Often, simply clicking this will fix the problem, or else provide a simple means to do so.

Acrobat Professional DC accessibility checker results panel

All well and good, so far.

So again, what’s the problem?

As useful as this tool is, there are many things that are vital to accessible document production that no automated tool can test for.

For example, it cannot tell you if:

  • Headings or lists are tagged as paragraphs
  • A table of contents is present and correctly tagged
  • Appropriate bookmarks are present
  • Page numbering is set correctly
  • Appropriate alt text has been assigned to images
  • Footnotes are accessible
  • Reading order is correct for screen readers
  • Reading order is correct for non-screen reader assistive technologies
  • Internal links have appropriate zoom settings
  • The correct document language has been set
  • An appropriate document title has been set
  • Background colours or image transparencies will cause problems for people requiring customized colour schemes

…and so on.

The bottom line

The above is by no means an exhaustive list of potential problems that will always get past an automated check. Yet, getting these things wrong will seriously compromise the accessibility of your documents.

This is why you cannot rely on automated checkers alone to benchmark the accessibility of your PDFs. If you are serious about accessibility, you must test them manually as well, using a wide variety of checks, including with a range of assistive technologies (not just screen readers).

Dig PDF accessibility training

We cover both automated and manual testing in detail in our Acrobat training course. For more details, or for a training quote, contact us today on hello@diginclusion.com or 01507 363356

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