What is a Tagged PDF and how do you know if you have one?

Tagging PDF documents is our primary output, our namesake and a large part of our vision to make the world more accessible. The process doesn’t change the ‘look’ of a document to a sighted person, instead it essentially explains what each piece of information is within the document and in what order these pieces of information come.


  • Adds ‘tags’ to guide assisting technology
  • Sets the navigation and reading order for complex documents
  • Follows general contrast and layout specifications
  • Allows for accessible and print versions of document to look the same
  • Can be protected to minimise user edits.


  • Allows for more design elements
  • Can describe complex tables and content
  • Alternate text of up to 4062 characters recognised
  • Visual representation the same across all devices and versions
  • Important information can not be easily altered once published.