What are PDF accessibility tags?
PDF accessibility tags are structural metadata embedded in a PDF that describe the document’s content to assistive technologies. They define the reading order, headings, tables, lists, and alternative text for images, allowing screen readers to interpret and navigate the document. Common accessibility tags include:| Tag | Purpose |
|---|---|
| Document structure tree | Defines the overall hierarchy and reading order of the document |
| Headings | Indicate section structure for navigation |
| Tables | Describe row and column relationships for data |
| Lists | Define ordered and unordered list items |
| Alternative text | Provide text descriptions for images and figures |
| Language | Specify the document language for correct pronunciation |
How Forerunner preserves accessibility
When you upload a PDF to Forerunner, it goes through a security sanitization process to remove potentially harmful content like embedded scripts and auto-run actions. Forerunner uses a selective sanitization approach that removes only dangerous elements while preserving the document’s accessibility structure tree.What’s preserved
- Structure tree - The full accessibility tag hierarchy that screen readers rely on
- Reading order - The logical order in which content should be read
- Headings and lists - Structural elements that aid navigation
- Table structure - Row and column relationships
- Alternative text - Text descriptions attached to images and figures
- Language metadata - Document language information
Forerunner preserves existing accessibility tags but does not add them. If a PDF is uploaded without accessibility tags, it will remain untagged after processing. To ensure your documents are accessible, add tags in your source application before exporting to PDF.
Why this matters
Public document sharing
Many communities share documents like Elevation Certificates, flood zone letters, and permit records through their public website. Preserving accessibility tags ensures these documents are usable by all residents, including those who rely on assistive technologies.Compliance
Federal and state agencies increasingly require that public-facing documents meet accessibility standards like Section 508 and WCAG. Forerunner’s approach ensures that documents uploaded with proper accessibility tags retain those tags after processing.Document integrity
Documents created with accessibility in mind represent significant effort by their authors. Forerunner’s selective sanitization respects that effort by keeping the document’s structure intact while still protecting against security threats.Best practices
Create accessible PDFs before uploading
Create accessible PDFs before uploading
Forerunner preserves existing accessibility tags but cannot add them. For the best results, ensure your PDFs are tagged for accessibility before uploading. Most modern word processors (Microsoft Word, Google Docs) can export accessible PDFs when configured correctly.
Check accessibility with Adobe Acrobat
Check accessibility with Adobe Acrobat
Use Adobe Acrobat’s built-in accessibility checker to verify your PDFs have proper tags before uploading. Go to Tools > Accessibility > Full Check to run an automated audit.
Add alt text to images in source documents
Add alt text to images in source documents
Add alternative text to all images in your source documents before exporting to PDF. This ensures screen readers can describe visual content to users who cannot see it.
Use heading styles for structure
Use heading styles for structure
Use heading styles (Heading 1, Heading 2, etc.) in your source documents rather than manually formatting text as bold or large. This creates proper heading tags in the exported PDF.
Related topics
- File types - Supported document types and formats
- Uploading files - How to upload documents to Forerunner
- Data security - How Forerunner protects your data
- Public website - Sharing documents publicly