This week, Joanna mines one of our most valuable resources—Simply Accessible’s usability panel—real users who test what we make to ensure our sites and apps are truly accessible. We asked them what barriers they face when accessing PDF documents on the web. Here’s what they had to say.
PDFs (Portable Document Format) present documents independent of software, hardware, or operating systems. Developed by Adobe in 1991, PDFs were proprietary until 2001, when they were released as an open standard. Now, they’re a pretty ubiquitous way to share branded or design-heavy documents across operating systems, the web, mobile, or through email.
Ah, but are they accessible? In their usual form, not really.
PDFs can have an excellent document structure, which makes them navigable by everyone including folks using screen readers. But, all too often good document structure is exactly what’s missing. Long documents don’t have headings to break up the content. Content gets read out of sequence. Images don’t have a text alternative, or the whole document is one giant scanned image. The list goes on.
The accessibility issues that pop up with PDFs often mirror those found in poorly structured HTML documents.
What actual users have to say
Usability testing with real users is a part of every Simply Accessible project. We’ve got a panel of folks from all over the world who use various assistive technologies and modifications to work with the web. These participants span a huge range of ages, professions, and disabilities including vision impairments, dexterity or mobility challenges, hearing challenges, or cognitive disabilities.
User testing is a huge part of what we do—who better to let us know how sites and apps are working than the end users we’re trying to serve?
We asked our fearless panel to weigh in on PDFs from their vantage point, and here’s what they had to say.
Good structure goes a long way
First off, we heard about how important structure is:
“I like when PDF files are properly tagged for accessibility, and when the different section titles are properly marked up as headings so that I can get to the information that I want quickly.”
– Male, 19-34 years old, JAWS user
What happens when a PDF isn’t tagged to have a good structure?
“I can open it, but my screen reader doesn’t always read it. JAWS often says ‘document empty’.”
– Female, 35-54 years old, JAWS user
She’s talking about a document that’s probably a scanned image. So, there’s something visible but nothing that she can use.
“What do I do when I run across a PDF? I swear creatively! Though I used to be able to access PDFs easily, as JAWS and Windows evolved, they don’t seem to like PDFs anymore. After the swearing, I usually get somebody else to access the thing on their computer.”
– Female, 35-54 years old, JAWS user
If there’s a problem, many people will blame their own software or hardware, or themselves. But when she describes something that stops working—the problem is with individual documents.
“Though PDFs are usually usable, they’re not as screen reader-friendly as most websites or Word documents. I try using my screen reader on the PDF, and if that doesn’t work, I usually give up. If it’s extremely important for me to access the information, I use the OCR (optical character recognition) feature to try extracting the content.”
– Female, 35-54 years old, ZoomText reader and magnifier user
When she knows that she needs the information in a PDF, you can see how far she’ll go to get at that important information—using OCR software. Other people we talked to also use OCR to access a PDF. Some even print it out and then scan it with Open Book (software that converts printed documents or graphic-based text into electronic text). Others use OCR in newer versions of JAWS. While this technology can be just amazing, it can sometimes also have problems with multi-column documents.
Plus, doesn’t this seem like an excessive amount of work to access something that should be simple?
Consider high contrast settings
Like all barriers to accessibility, PDFs don’t just impact people who use screen readers.
“PDFs are frustrating. The document colour doesn’t come through inverted with an ‘inverted colour high contrast’ setting on the Windows OS. Any time I receive a confirmation for a reservation as an attachment in a PDF format, it’s unreadable to me. It usually displays with a white background and black text, but the brightness of the white background takes over and masks the black text. Any sort of flyer or document that’s posted in an email or on a website as a PDF isn’t visible with an inverted colour scheme on a Windows operating system. This is very frustrating as an increasing number of important documents are sent as PDFs.”
– Female, 35-54 years old, Windows High Contrast user
High Contrast is a built-in accessibility setting on Windows. The colour scheme uses a black background, reverses the text, and removes CSS backgrounds which makes everything easier to read. It’s easy to turn on with just Left Shift+Left Alt+Print Screen. If you’re not using Windows, here’s what it looks like:
It turns out the default settings of Adobe Reader ignore a user’s High Contrast settings on Windows. And, the options to adjust it are buried deep in the many available preferences. When you include a PDF on your site, it may create a real barrier for people who use high contrast with default Acrobat settings.
If you do use High Contrast on Windows and are trying to access a PDF, we’ve put together instructions on how to change the defaults in Adobe Reader to work better with high contrast.
As a format on mobile devices, PDFs are less than ideal. From a person with low vision:
“I can’t easily read a PDF on a mobile. I would need to use a hand-held magnifier over the mobile screen.”
– Female, 55+, ZoomText user
For a VoiceOver user, the KNFB Reader makes access to PDF documents easier on mobile devices.
“I use iBooks with the iPhone as well as the KNFB Reader to read PDF documents, especially ones with images.”
– Male, 19-34 years old, VoiceOver user
But, ideally, the PDF should have an accessible structure and not need the OCR power of the KNFB Reader.
This is a lot of information to digest, and we don’t want to leave you struggling with what to do next. Here are some basic starting points to consider.
- Don’t use the PDF format if you can help it. If you can create a web page, do that instead. A properly formatted web page—including good HTML heading structure and text alternatives for images—is inherently more accessible to a broader range of people.
- If it’s intended for print, think about providing multiple print formats. When you have a PDF document that’s meant to be used as a printed document, offer a large print format for people with low vision.
- Make it clear that a link goes to a PDF. Use a foreground icon with an alt attribute to let people know the file is a PDF ahead of time. Also, let people know what size the document is in advance.
<a href=”AnnualReport2016.pdf”>Our 2016 Annual Report <img src=”pdf-icon.png” alt=”PDF”> 2 MB</a>
- All of the usual web accessibility principles and best practices apply for a PDF document. You’ll need proper colour contrast, text alternatives for images and any embedded media, and good document structure like headings. This is where making a well-structured HTML document might require less work.
What have you come across in your practice to help make PDFs more easily accessible? Share your strategies in the comments below.