August 2008

Access to PDF Content

By Andrew Kirkpatrick, Senior Product Manager - Accessibility, Adobe

The PDF file format provides robust support for needed information to enable users with various disabilities to gain access to content delivered via PDF files. However, some people believe that PDF is an inaccessible file format. This belief is often based on outdated or incorrect information. In this article, I aim to clarify what the strengths and limitations of PDF are.

The PDF file format includes a mechanism for conveying important information about documents. Some of the most important information that users with disabilities need includes equivalents for images, information about document semantics such as heading elements, lists, and tables, designation of document language, and a linear reading order for the content. Adobe Reader is able to correctly interpret this information and conveys it to the assistive technologies that users depend on (including screen readers).

Adobe Reader also provides additional features to help users access PDF documents, including support for high-contrast views of PDF documents, a built-in reading tool, a document zooming and reflow tool, and the ability to add accessibility information automatically through a programmatic process.

Not all PDF documents are accessible, but this is most often a factor of PDF authoring rather than a problem with Adobe Reader or of the file format itself. PDF documents need to be created by tools that support the accessibility features of the PDF file format. There is a growing collection of tools available for authors to use to create PDF documents that include accessibility information and that support "tagged PDF" (tagged PDF refers generically to a PDF document that includes accessibility information).