6.10 Difficulties in Accessing Portable Document Format (PDF)

Affected Group: All Persons with Disabilities

PDF documents should only be used for certain situations, in particular when there is a piece of content that suggest user to download and read offline. In this way, PDF documents can be helpful for persons with disabilities because they can download and read them with the assistive functions built into PDF reading software.

It is essential to ensure that PDF documents are accessible to assistive technologies, such as screen readers in a correct reading order. We should produce a PDF document from a text-based source document and alternative text should be provided for images (except for decorative images), so that it is readable by Braille devices used by persons with visual impairments. Image-based documents, such as TIF files produced by scanning, should be converted into text-based documents with Optical Character Recognition (OCR) software before producing the PDF document.

PDF documents also need to be correctly structured and tagged to be accessible. Software such as Adobe Acrobat has many features that allow checking and adjustment of structure and tagging within a PDF document. The techniques of making accessible PDF document is available at www.w3.org/WAI/WCAG22/Techniques/#pdf.

Any content that you would like people to read online should be delivered as standard HTML webpages rather than PDF documents.

An image showing poor quality scanned text.