Providing links and link text using the Link annotation and the /Link structure element in PDF documents

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.1 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.1.

Applicability

PDF documents that contain links

This technique relates to:

Description

The purpose of this technique is to show how link text in PDF documents can be marked up to be recognizable by keyboard and assistive technology users. That is, the link information is programmatically available to user agents so that links are recognizable when presented in a different format. This is typically accomplished by using a tool for authoring PDF.

Links in PDF documents are represented by a Link tag and objects in its sub-tree, consisting of a link object reference (or Link annotation) and one or more text objects. The text object or objects inside the Link tag are used by assistive technologies to provide a name for the link.

The simplest way to provide links that comply with the WCAG success criteria is to create them when authoring the document, before conversion to PDF.

However, in some cases, it may not be possible to create the links using the original authoring tool. In these cases, Adobe Acrobat Pro can be used to create the link. But, because the tooltip created using the Link dialog in Adobe Acrobat Pro is not accessible to screen readers, be sure that the link text or the link context makes the purpose clear.

In all cases, link purpose should be made clear as described in the general techniques:

Examples

Resources

Resources are for information purposes only, no endorsement implied.

Tests

Procedure

For each hyperlink, verify that the link is correctly tagged and the link text is properly exposed:

  1. Read the PDF document with a screen reader, listening to hear that the link is read correctly and that it describes the purpose of the link (i.e., its destination).
  2. Visually scan the tag tree to verify that the link is tagged correctly and the link text is exposed (for screen magnifier users and sighted users with cognitive disabilities).
  3. Use a tool that is capable of showing the /Link entry value to open the PDF document and view the hyperlink and link text.
  4. Use a tool that exposes the document through the accessibility API and verify that the link has the correct link text.
  5. Tab to each link and check that it can be followed to its target by pressing Enter.

Expected Results

  • #1 or #2 or #3 or #4 is true.
  • #5 is true.