PDF Accessibility Checker – Learn PDF/UA Standards

An accessible PDF must have: Tags: Structural tags (headings, paragraphs, lists) that define document hierarchy Reading order: Logical sequence that screen readers follow Alt text: Descriptions for all images, charts, and non-text content Language: Document language specified for proper pronunciation Document title: Meaningful title (not just filename) Accessible forms: Form fields with labels and tooltips Color contrast: Sufficient contrast ratios (4.5:1 minimum) Security: No restrictions that block screen readers Bookmarks: Navigation aids for long documents Tables: Proper table headers and structure PDFs meeting these requirements comply with PDF/UA (Universal Accessibility) standard.

Best practice is to create accessibility in the source document: Microsoft Word: Use built-in heading styles (Heading 1, Heading 2, etc.) Add alt text to images (Right-click → Edit Alt Text) Use built-in list tools (not manual bullets) Create tables with header rows Set document language (Review → Language) Add document title (File → Properties) Run Accessibility Checker (Review → Check Accessibility) Export: File → Save As → PDF → Options → check "Document structure tags for accessibility" Adobe InDesign: Use paragraph styles for headings Add alt text in Object Export Options Tag reading order properly Export as Adobe PDF (Print) with accessibility enabled

Use these tools to verify PDF accessibility: Professional Tools: Adobe Acrobat Pro: Tools → Accessibility → Full Check (most comprehensive) PAC 3: Free PDF Accessibility Checker from Access for All (Switzerland) PAVE: Free PDF Accessibility Validation Engine CommonLook PDF: Professional remediation and validation tool Screen Reader Testing: NVDA (Windows): Free, widely used JAWS (Windows): Professional screen reader VoiceOver (Mac): Built-in macOS screen reader Quick checks: Try selecting text (if you can't select, it's probably an image) Use Adobe Reader's Read Out Loud feature Check File → Properties for Title and Language

PDF tags are structural elements that define the document's content hierarchy, similar to HTML tags: Common PDF tags: <H1> to <H6>: Heading levels <P>: Paragraphs <L>, <LI>: Lists and list items <Table>, <TR>, <TD>: Tables <Figure>: Images and graphics <Link>: Hyperlinks Why tags matter: Screen readers use tags to navigate and announce content Defines reading order for assistive technology Allows users to jump between headings, lists, tables Required for PDF/UA compliance Improves reflow for mobile devices Untagged PDFs are essentially images to screen readers - users can't navigate or understand structure.

Scanned PDFs (images of pages) require OCR (Optical Character Recognition) and additional work: Run OCR: Use Adobe Acrobat's Enhance Scans feature or similar tool Add tags: After OCR, add structural tags (usually requires Acrobat Pro) Set reading order: Define logical sequence for content Add alt text: Describe images, charts, and diagrams Verify text: Check OCR accuracy and fix errors Add metadata: Set title, language, and other properties Better approach: If you have the original document, create a tagged PDF from the source instead of scanning. Scanned PDFs require significantly more work to make accessible. Alternative: Consider creating an accessible HTML version alongside the PDF for better accessibility.

PDFs present unique accessibility challenges: Not web-native: Require special reader software Complex structure: Tagging is not automatic like HTML Poor mobile experience: Don't reflow well on small screens Reading order issues: Multi-column layouts confuse screen readers Forms: PDF forms are harder to make accessible than HTML forms Remediation: Fixing accessibility requires professional tools Best practice: Provide HTML versions of content when possible. Use PDFs only when necessary (official documents, printable forms, etc.). When PDFs are required: Invest in proper tagging and testing to ensure accessibility.