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Well-Tagged PDF (WTPDF) cover image.

Game-changing new free specification enables interoperable reuse and accessibility for PDF

Well-Tagged PDF (WTPDF), a common specification for both reuse and accessibility, is a massive leap forward for PDF technology.
About the author: The PDF Association staff delivers a vendor-neutral platform for PDF’s stakeholders, facilitating the development of open specifications and ISO standards for PDF technology. The staff are located in Germany, the … Read more

The PDF industry is taking a massive leap forward in addressing the need for a common specification for reuse and accessibility in PDF through the PDF Association’s Well-Tagged PDF: Using Tagged PDF for Accessibility and Reuse in PDF 2.0 (WTPDF) specification.

This new document provides developers with comprehensive requirements for software that seeks to create or consume fully reusable and accessible PDF 2.0 files in an interoperable manner. It’s the culmination of ten years of development within the PDF Association by the PDF/UA Technical Working Group (TWG) and PDF Reuse TWG.


PDF’s Tagged PDF feature, introduced to the PDF file format in 2001, makes it possible to add semantic markup to content on PDF pages, enabling accessibility, semantic analysis and reuse.

To date, the primary focus for Tagged PDF was accessibility, and the latest specification for PDF accessibility was based on ISO 32000-1 (PDF 1.7). No such specification existed for PDF 2.0, nor was there any specification providing guidance on how to create interoperable reusable content in PDF files.

PDF 2.0, the most recent specification of the PDF file format, introduced powerful new capabilities to Tagged PDF that enhance PDF’s capacity to deliver reusable and accessible content. With the introduction of WTPDF, the PDF Association addresses the critical needs of both reuse and accessibility, unlocking the full power of PDF 2.0.

The Well-Tagged PDF 2.0 (WTPDF) specification

Cover of the Well-Tagged PDF specification.The WTPDF specification is a freely available publication. Its rules specific to the reuse and accessibility use cases are expressed as conformance levels. A PDF file can conform to both reuse and accessibility rules, ensuring the best outcome for all use cases.

As this new specification’s rules regarding accessibility are mirrored in the forthcoming ISO 14289-2 (PDF/UA-2), this new specification is the canonical reference for both PDF reuse and PDF accessibility in PDF 2.0.

Use cases for this specification include:

  • ensuring accessibility of PDF 2.0 files;
  • managing reflow of content (e.g., for responsive layout on mobile devices);
  • derivation to other formats, including HTML;
  • interoperable structuring of unstructured content;
  • content and data extraction (e.g., copy-and-paste);
  • selection, annotation and redaction;
  • enhancing searchability;
  • unlocking content and semantics for use by AI;
  • change-tracking;
  • round-trip editing (e.g., word processor → PDF → word processor).

The experts contributing towards this effort in the PDF/UA TWG and PDF Reuse TWG envision this new specification as the authoritative guide to the use of tagged PDF 2.0 files for accessibility, reuse analysis and extraction.

Download WTPDF today!

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