We avoid PDFs because:
they cannot meet the range of users' accessibility needs, for example, users cannot change colours or font size
- they usually give people a poor user experience, especially on mobile
- many browsers, tools and extensions do not work with them – they often have problems with zoom, scroll, audio, image and keyboard navigation
- they make it difficult for users to navigate to the rest of the website
- they may take users away from the website, opening in a new tab, window or software – and not all users have the right software
- they are hard to maintain and update, so users may get out of date and unreliable content
- if users find PDFs in search results, they get them without any supporting context or material, such as who the publisher is
- search engines may not rank PDFs as highly in search results as HTML pages
- it's difficult to collect data on how people use PDFs, and that makes it difficult to identify problems and improve them
There are exceptions to the rules, such as documents with images, graphs etc. these need to be accessible PDFs at the very least. Where possible turn the content into a webpage.
If needing to display both documents, then a HTML version and original
Put that it is a PDF in brackets, file size e.g. (PDF, 34KB)
Alt text, is read out by screen readers or displayed if an image does not load or if images have been switched off.
All images, except decorative images (which are images that do not provide any value to a user), must have alt text that:
- tells people what information the image provides
- describes the content and function of the image
- is specific, meaningful and concise
Use normal punctuation, like commas and full stops, so the text is easy to read and understand.
- include the name of the photographer or person who created the image
- start with ‘Image of’, ‘Graphic of’ or ‘Photo of’
- repeat information from the page
- include extra information not in the image