Section 508 Checklist for Accessible PDF

What is reviewed during a Section 508 PDF audit and where documents commonly fail.

Section 508 PDF evaluations are often described as a checklist, but accessibility reviews involve more than checking boxes.

This article outlines the core criteria typically reviewed during a Section 508 PDF evaluation and explains why many PDFs fail despite appearing compliant.

Document structure and tagging

One of the first items reviewed in a Section 508 PDF evaluation is document structure.

Reviewers typically check whether:

  • The PDF is properly tagged

  • Tags reflect the logical structure of the document

  • Headings are identified semantically

  • Lists and paragraphs are correctly marked

Untagged or incorrectly tagged PDFs consistently fail accessibility reviews.

Reading order

Reading order determines how content is presented to screen reader users.

During a review, evaluators check whether:

  • Content is read in a logical sequence

  • Columns, sidebars, and footnotes are ordered correctly

  • Visual layout matches programmatic order

Incorrect reading order is one of the most common Section 508 failures.

Images and alternative text

Images must include meaningful text alternatives when they convey information.

Checklist items typically include:

  • Presence of alternative text

  • Accuracy and relevance of descriptions

  • Decorative images marked appropriately

Missing or incorrect alternative text can prevent users from understanding key content.

Headings and navigation

Accessible PDFs must support efficient navigation.

Evaluators typically check:

  • Proper heading hierarchy

  • Consistent use of headings

  • Ability to navigate by headings using assistive technology

Visually styled text that is not tagged as a heading often causes navigation failures.

Tables

Tables must be structured so relationships between data are clear.

Checklist reviews often include:

  • Proper table tagging

  • Identification of header cells

  • Logical reading order within tables

Improperly tagged tables are difficult or impossible for screen reader users to interpret.

Forms and interactive elements

If a PDF includes form fields, additional criteria apply.

Evaluations typically review:

  • Field labels

  • Tab order

  • Instructions and error messaging

  • Keyboard operability

Forms are frequently cited as a high-risk area during Section 508 audits.

Document metadata and language

Metadata supports accessibility and usability.

Reviewers often check:

  • Document title

  • Language identification

  • Security settings that do not interfere with assistive technologies

Missing metadata can cause PDFs to fail compliance checks.

Why checklists are not enough

Checklists are useful for identifying common issues, but they cannot assess usability.

Accessibility evaluations also require:

  • Manual inspection

  • Assistive technology testing

  • Review of content meaning and clarity

A PDF may technically pass a checklist and still be difficult to use.

Conclusion

A Section 508 PDF checklist highlights key accessibility requirements, but true compliance depends on how those requirements are implemented.

Organizations should view checklists as a starting point, not a substitute for comprehensive accessibility review.

Accessibility Testing Note

Section 508 PDF evaluations commonly include both checklist-based checks and manual testing with assistive technologies.