Validating PDFs for Accessibility
The most efficient way to create an accessible PDF is to start with an accessible source file (such as a properly formatted Microsoft Word document or InDesign) and export it as a tagged PDF. This method preserves your accessibility features while keeping the source document easy to edit.
If you are working with an existing PDF, or need to verify and fix final formatting, you can manage and add accessibility features directly using Adobe Acrobat Pro.
General Checkpoints:
- Accessible Properties:Does the document have structural headings, accessible links, and selectable (not scanned/image) text?
- Correct Tagging:Is the document structure accurately mapped in the tag tree?
- Automated Verification:Have you run the built-in automated accessibility checker?
- Manual Review:Have you manually verified the reading order, color contrast [link to color contrast page], and accuracy of the tagging?
Step-by-Step Validation in Adobe Acrobat Pro
1. Run an Initial Accessibility Check
Before making edits, run Acrobat's Accessibility Checker to identify potential issues and establish a baseline.
- Open the Accessibility tool.
- Select > Accessibility Check (or Full Check).
- Review the report for common issues such as missing alternative text, untagged content, missing document language, or reading order concerns.
- Use the report to guide your remediation efforts throughout the review process.
Resource: Adobe Help: Create and Verify PDF Accessibility
2. Review Document Properties
A compliant PDF requires foundational metadata so assistive technologies can read it correctly.
- Descriptive Title:Ensure the document has a clear, public-facing title (distinct from the file name).
- Document Language:Set the correct default language so screen readers use the right pronunciation rules.
- Selectable Text:Verify the text can be highlighted and read. If it's a scanned image, runRecognize Text (OCR)first.
Resource: Adobe Help: PDF Properties and Metadata
3. Review Tag Structure
Tags provide the hidden blueprint that tells a screen reader what each piece of content is (e.g., Headings, Paragraphs, Lists, Tables).
- Heading Hierarchy:Ensure headings follow a logical nested order without skipping levels.
- Data Tables:Verify that tables use <Table>, row <TR>, header <TH>, and data <TD> tags. Never use tables purely for visual layout.
- Links:Confirm links are embedded inside standard paragraph tags using the proper <Link> tag structure.
Resource: Adobe Help: Editing Document Structure with the Content and Tags Panels
4. Review Reading Order
The visual layout of a page does not always dictate how a screen reader will interpret it.
- Open the Order Panel or use the Reading Order Tool to verify that content is numbered in the sequence it should logically be read.
- Drag and drop items within the panel to fix any skipped or out-of-order content block sequences.
Resource: Adobe Help: Touch Up Reading Order Tool
5. Review Alternative Text
Assistive tools cannot interpret images without a text substitute.
- Provide distinct, meaningful Alternative Text (Alt Text) for images, charts, and diagrams that convey critical information.
- Mark purely decorative elements (like lines, borders, or background shapes) as Artifacts so screen readers will intentionally skip them.
Resource: Adobe Help: Add Alternative Text and Metadata to PDFs
6. Run the Acrobat Accessibility Checker
Let Acrobat do a sweep for technical errors before your final sign-off.
- Navigate to the Accessibility toolsets pane and select Accessibility Check (or Full Check).
- Review the generated report panel to locate and fix automatically detected failures (such as missing alt text or untagged content).
Please Note:Automated checkers are great for catching explicit omissions, but they cannot evaluate context. Always perform a final manual review to ensure your alt text makes sense and your reading order is genuinely logical!