Files in Portable Document Format (PDF) are commonly used on the web as they retain their structure across computers, making it easy to preserve print layout. 

A common request for conversion of materials centres on access to PDF files supplied by publishers.

Several years ago, these files were inaccessible to people who used screen readers. 

Newer versions of both Adobe and screen reading software now make PDF files more accessible.  Acrobat Reader 6.0 includes a simple text-to-speech reader, as well as the ability to convert the file to text. 

The level of accessibility of PDF files still depends on how they are created. See the resources at the bottom of this page for more information on this.

It remains a good policy to offer documents in an alternative format (eg. text or Word document files, or HTML) when providing PDF versions.

More information

The Pros and Cons of PDF Files

Andrew Downie, Roundtable Conference 2004

http://www.e-bility.com/roundtable/conf_proceedings04.php

This paper is available as a MS Word file, from the list of conference proceedings, and aims to reduce the confusion about access to PDF files by screen reader users.  It describes the progression of PDF files from inaccessible to 'largely accessible'.

Adobe Acrobat Accessibility Techniques

WebAIM

http://www.webaim.org/techniques/acrobat/

http://www.webaim.org/techniques/acrobat/reader

The first link is to a clearly written, comprehensive guide to creating PDF files that are accessible to people with a variety of disabilities.  The second link is to an article on the accessibility features of Adobe Reader 7.

Adobe Resources

The Adobe web site offers a range of resources on accessibility.  The direct links are provided here as they can be difficult to find on the site.

Online Conversion tools http://www.adobe.com/products/acrobat/access_onlinetools.html

PDF files can be converted to text or HTML, with the results either sent via mail, or displayed online.

Make Accessible plug-in (creates a tagged PDF file from an untagged file)

http://www.adobe.com/support/downloads/detail.jsp?hexID=88de

Tagged PDF files can be more accessible to screen readers.  They can also be saved as RTF (Rich Text Format) files.

Paper Capture plug-in

http://www.adobe.com/support/downloads/detail.jsp?ftpID=1907

This plug-in performs optical character recognition on PDF image files, converting the image to text.

Accessibility Training Resources (including a resource for people with disabilities)

http://www.adobe.com/enterprise/accessibility/training.html

Resources available include guides for creating accessible PDF files, and a guide for people with a disability on reading PDF documents.

For more important information on converting materials, go to:

What to consider when converting materials in accessible formats (CD)