Web Services

PDF on the Web

About PDF

PDF (Portable Document Format) is extremely popular because it can be produced by many different operating systems and preserves format for printing. However, it does have some issues for people with disabilities, particularly files made some time ago. PDF can be used on the web, but it should not be the sole source of information.

  • Make sure your PDF is accessible to people with disabilities
  • Consider other formats, such as HTML

If providing PDF files

Not many people are on dial-up modems now, particularly university students, but many internet packages throttle back to extremely slow speeds once the set quota has been exceeded. Other packages get very expensive at this point. Therefore keep your file sizes small.

  • Optimise any images in the PDF
  • Distil the file at 72dpi (dots per inch) This is fine for viewing text online, but you will need Distiller or Acrobat Professional to do this
  • Also subset any embedded fonts
  • 'Save As' – removes content saved with the file
  • Break files into chapters
  • Convert to RTF from Acrobat - you will get a smaller file (but loss of format)

Later versions of Acrobat will also let you reduce the document size as a feature. Under 'Document' there is an option to 'Reduce file size. Finally, when you put your document online, include the file format and size in the link text.

Write Searchable Documents

Make sure your PDF is accessible, and it will perform much better in search engines. To generally optimise your files for search engines:

  • Fill out the document 'Properties' – displayed in search results
  • Use Structural elements properly in Word, PDF eg.:
    -  Headings
    -  Table of Contents
  • Split large documents into sections:
    -  Get more content indexed
    -  Documents will load faster
  • Provide alt text for images:
    -  Adds more 'indexable' text to your page
    -  If alt text is done well it increases accessibility for people with disabilities