Common Accessibility Challenges in PDF Documents

PDF accessibility issues rarely happen one at a time. A single PDF may contain several problems that make it difficult for people using assistive technology to access and understand the content. These issues typically fall into a few common categories.

Structural and Semantic Issues

Many accessibility problems start with the document's structure. Untagged PDFs, incorrect reading order, missing language settings, and poorly structured tables can make it difficult for assistive technology to understand and present content correctly.

Without proper structure, screen readers may not recognize headings, lists, tables, or the relationships between different pieces of content. As a result, users may find the document confusing and difficult to navigate.

Another common issue is image-only PDFs. Scanned documents often contain pictures of text instead of actual text. While optical character recognition (OCR) can convert these images into readable text, the document may still require tagging and other accessibility improvements.

Navigation and Orientation Challenges

Good navigation helps users move through a document quickly and efficiently, especially when the document is long.

Missing bookmarks, tables of contents, clear heading structures, or meaningful document titles can make it harder for users to understand how a document is organized and find the information they need.

People using assistive technology often navigate by headings, bookmarks, and other structural elements rather than reading a document from beginning to end. When these navigation features are missing, even well-written content can be difficult to use.

Non-Text Content and Visual Design Barriers

Images, charts, diagrams, and other visual elements need text alternatives so that users who cannot see them can still access the information they contain.

Missing or poor-quality alternative text can prevent users from understanding important content.

Visual design can also affect accessibility. Low color contrast, relying on color alone to communicate information, and complex page layouts can make documents harder to read for people with low vision, color vision deficiencies, or cognitive disabilities.

Decorative elements that are not marked as artifacts may also create unnecessary distractions for screen reader users.

Interactive Content and User Input Issues

Forms and interactive PDFs can present additional accessibility challenges.

Missing field labels, confusing tab order, unclear instructions, and inaccessible error messages can make forms difficult or impossible for some users to complete.

Links can also create barriers when the link text does not clearly describe its destination. Phrases such as “Click Here” or “Read More” provide little context for users navigating links with assistive technology.

Accessibility Across Viewing Environments

A PDF that works well in one environment may not work the same way in another.

Differences in screen size, magnification settings, PDF viewers, and assistive technologies can reveal accessibility issues that are not immediately obvious during document creation.

Testing PDFs in different environments helps ensure that users can access content regardless of the device, software, or assistive technology they use.

Accessibility Starts Before Remediation

Many PDF accessibility issues begin during document creation rather than during remediation. Decisions about structure, layout, content organization, and export settings all affect the accessibility of the final PDF.

Building accessibility into the document creation process can reduce remediation work, improve document quality, and support conformance with standards such as PDF/UA and WCAG. Accessibility is most effective when it is considered from the start, not added after a document has already been published.