Usability and Accessibility Issues with PDFs

PDF illustrationOne of the most popular file formats used in working and learning environments — PDF, which stands for Portable Document Format — has significant limitations when repurposed for web content.

PDF files have become the “informational currency” used to run many organizations. They are easy to make. Anyone can use a word processing application such as Microsoft Word or an online document editor such as Google Docs and save their work as a PDF. By doing so, appearance and layout of text, type font, any any graphical elements such as illustrations and photographs will be preserved in the file. They’re handy to use as email attachments to distribute flyers, handouts or manuals.

As tempting as it may be, though, PDFs should not be used to present content that users will read online. That content should be in HTML on web pages.

Why? Historical perspective is helpful: When the PDF file format was first invented in the late 1980s and commercialized in the early 1990s, the internet was still in its infancy. Offices, businesses and classrooms relied heavily on printed materials. PDFs were a technological breakthrough intended to make it easier to produce and share source files for printed assets.

However, the PDF file format is not intended to address the needs of current web users. Linking to a PDF that is provided as a source file for visitors to print is really the only reason that content should be offered as a PDF. Most PDFs on the web don’t fit that use case. Instead, they exist because they seem easy to create, are leveraged as temporary workaround solutions for content management, provide control over design, or remind us of familiar print formats. The downside is that PDFs aren’t user-friendly or accessible.

Drawbacks of PDFs as web content

A few reasons why PDFs are not the best tool for websites includes:

  1. Users strongly dislike PDFs. They create a jarring user experience, often opening without warning. They typically lack any navigation or a clickable table of contents, which makes it difficult to find things. (While it is possible to use Command or Control + F to do a keyword search within PDFs, this tactic is not behavior typical among all web users.)
  2. PDFs are inherently inaccessible to web users who are visually impaired or blind. Colors and text size are challenging to adjust, many files do not have the tab order set up correctly for screen readers, images lack alt text, and diagrams lack long descriptions.
  3. They are bad for your search engine optimization strategy. A significant proportion of traffic to most web content arrives not by users navigating through the website menu, but by searching Google for keywords of interest. PDFs lack structured data, are often large and load slowly, and aren’t optimized for mobile devices. They do not rank well in search results, so the same content presented in HTML will typically perform better in search than if it is presented in a PDF.
  4. PDFs are not mobile-friendly. They don’t change size in a responsive way to fit the browser width, which is the major consideration for mobile users. For websites that receive significant traffic from mobile devices, this is a deal-breaker.
  5. Content is more challenging for web users to edit and reuse. Say, for example, there’s a pithy quote or phrase in your content that a user would like to copy and share with someone else. That’s great – but cutting and pasting text from PDFs often produces unexpected results, resulting in frustration.
  6. PDFs aren’t truly designed for reading on screens. Remember, the digital realm is just a transitory phase for this file format. It is ultimately meant to produce a tangible form, so the specifications of this file type are optimized to support printing.
  7. They are difficult for web users to navigate when seeking specific information. Because the website navigation menu doesn’t appear when viewing the file, users can become disoriented. Visitors who open PDFs directly from search also don’t have context for the information or access to related content.
  8. PDFs give you very limited metrics about how much web users are engaging with them. It not possible to track analytics measuring engagement because data such as depth of scroll, how long the file was viewed, and what links were clicked cannot be captured.
  9. PDFs are easy to overlook when you are maintaining content. They are less likely to be kept up to date than HTML, and multiple outdated versions are often left on websites. Have you ever encountered a PDF online that gave incorrect dates, addresses or instructions? It can be frustrating indeed.

Notably, many of these same issues apply to other linked files as well, including Word documents and PowerPoints.

Gateway pages help prepare expectations when PDFs are used

If you have a strong reason to keep a PDF on your site, consider building an HTML gateway page with a short summary and link to the file. These pages will allow users to quickly understand the important aspects of the linked file, avoids the surprise of an unexpected PDF opening, and can provide information about file size, last update, and number of pages that will help users decide whether they want to download the file.

Limitations of PDFs used for forms

Once upon a time, forms were by necessity printed sheets or cards that were filled out by hand, often requiring a handwritten signature. But forms exist to capture information, and the more onerous it is for a user to fill out a form the less likely they are to do so. Today, many web users will balk at forms that require printing or signing, scanning, and uploading. Forms are more accessible and user-friendly in web format. Online forms are easier to navigate and are more accessible when they are in HTML. Form creators can also use conditional logic to hide and show relevant fields, or allow for adjustable height fields and calculations. Users can cut and paste information and use autocomplete. Overall, HTML forms provide a better and more efficient experience. (One note: Be sure to consider the best options for data collection and storage based on the type of information you are collecting.)

Keep the end user in mind

While PDFs are essential for material destined for print, they are inherently disconnected from other HTML web content and elude updating and editing by the same processes or consideration as the rest of the site content. Use HTML to give your users a better experience with content that loads quickly, maintains a consistent viewing experience, is designed for web and is accessible. As an added benefit, you’ll have more information on how users interact with that content and will encourage reading online (which saves paper!).


Additional Reading