What Is a Tagged PDF?
Learn what PDF tags are, why screen readers need them, and how tagged PDFs connect headings, paragraphs, tables, figures, links, and reading order.
Tags give the PDF a logical reading structure
PDF pages are often stored as drawing instructions. Without tags, assistive technology may see text fragments in a confusing order or miss relationships such as table headers and image descriptions. A tagged PDF adds semantic structure on top of the visual page.
- ✓Document and section containers
- ✓Headings such as H1, H2, and H3
- ✓Paragraphs, lists, and list items
- ✓Table rows, header cells, and data cells
- ✓Figures with alternate text
The structure tree should match the visible document
Good tagging is not just adding any tags. The structure should follow the visible document: title first, sections in order, table cells grouped correctly, decorative graphics marked as artifacts, and meaningful images represented as figures with concise alt text.
Tagged output must be physical, not just a dashboard score
For remediation, the corrected export needs actual PDF objects such as StructTreeRoot, StructElem roles, language, title metadata, and figure Alt entries. If those changes are only stored in an internal database, external tools and screen readers will not benefit.
Tagged PDFs also help RAG pipelines
The same structure that helps screen readers can improve AI ingestion. Headings, reading order, tables, and page references make it easier to create retrieval chunks that preserve source context.
What to verify before publishing
- 1Look for a document structure tree
- 2Check that headings are real heading tags
- 3Confirm figures have meaningful alt text or are decorative
- 4Verify tables expose headers and cells
- 5Export and re-check the fixed file
Questions about this guide
Can a PDF be accessible without tags?+
Most multi-page or structured documents need tags. Very simple PDFs may expose enough text for basic reading, but reliable accessibility requires a logical tag tree.
Does OCR create a tagged PDF?+
OCR can make scanned text selectable, but it does not automatically create correct headings, tables, figure alt text, or reading order.
Can tags be added after a PDF is created?+
Yes. PDF remediation adds or corrects tags in existing PDFs, then re-checks the exported file.