The Adobe Portable Document Format (PDF) provides a convenient way to transport, view
and print electronic documents. PDF files are typically created in other applications
like Microsoft Word or PowerPoint. The following best practices are provided to help
you maximize the accessibility of your PDF documents.
Converting to PDF from Word
The best way to create an accessible PDF is to use Microsoft Word. If you format your
document following the best practice recommendation listed in Creating Accessible Word Documents, your PDF will be off to a good start.
Scanning a PDF
A scanned PDF is a picture of text. As such, a screen reader cannot read the text,
and the text in the image is much too long to enter as alt text. PDFs made by scanning
a document with an office copier are not accessible unless you take a few extra steps
Use Optical Character Recognition to make a scanned PDF accessible
- In order to make a scanned PDF accessible, the first step is to use OCR to convert
the image into text.
- To see if a PDF has already been converted and is readable by a screen reader, try
to use your mouse to highlight the text. If you can highlight pieces of text, OCR
has been used. If you cannot highlight lines of text, then you are looking at an image.
- To test the accuracy of the OCR conversion, copy and paste the highlighted text into a document and check
to see if the text/characters were accurately converted.
Tagging your PDF
- Once a PDF has been converted, the next task is to add tags. Tags allow the author
to identify headings, alt text, lists, etc. They essentially give the document structure
and allow the reader to easily navigate the document.
- To determine whether a PDF is tagged, open it in Adobe Acrobat or Adobe Reader and
go to Document Properties. In the lower left corner of the Document Properties dialog,
Tagged is either Yes or No.
- To add tags to a PDF you need to use Adobe Acrobat.
- Fixing Inaccessible PDFs Using Adobe Acrobat Pro
Resources on the Web