How to make PDFs accessible

Maria Drummond
Monday 15 July 2019

PDF files published on the University of St Andrews website must meet accessibility standards. This is so the website, and all the content within it can be used by as many people as possible.

Considering that there are hundreds of PDF files on the University website, it’s imperative that they’re also accessible. This post is a brief how-to guide on how to do just that.

In digital communications, we frequently rely on advice provided by GOV.UK, who, in relation to PDF accessibility, suggest publishing information as HTML rather than as PDFs:

“Wherever possible, publish as an HTML webpage. It’s the best way to reach as many people as possible. Documents like PDFs make your content harder to find, use and maintain. And it can be difficult for users to customise them for ease of reading, and often they do not work very well with assistive technologies like screen readers.”

However, it is important to recognise that not all University content is suitable for HTML, and that all potential web content is considered on a case-by-case basis. If you’re a member of staff at the University and would like some guidance about this, please contact [email protected].

1. Write for accessibility

The first step in creating any accessible document is to ensure the content within that document is accessible. In summary, your content must:

  • Use simple language. As Lewis succinctly states in his blog post on designing for users on the autistic spectrum: “writing clear, plain language will mean your content is understood by more people.” You can find out more information about plain English on the Plain English Campaign website.
  • Use alternative (‘alt’) text. Alt text provides a textual alternative to non-text content in web pages and is used by screen readers for those with visual impairment and by browsers to describe images when they are loaded incorrectly.
  • Simplify the document. Quick wins for this include:
    • keeping sentences and paragraphs short
    • using sentence case
    • avoiding unnecessary underlining, emboldening or italicisation.

If you’re using Microsoft Word, you can run the accessibility checker to check your formatting and fix any problems.

2. Structure your document for accessibility

Using plain language is only the first step in making your document accessible. Simplified formatting should also be used to improve the reading experience for everyone.

  • Use structural formatting. Where appropriate, headings, subheadings, bullet points and numbered lists should be used to break up text.
  • Create a table of contents.
  • Always left-align text when working with languages that are read left to write.
  • Add alt text to describe images or other non-text web content.
  • Use colour appropriately. Colours should sufficiently contrast and must never be used solely to convey meaning.

How to add alt text to a Microsoft Office document in Windows and Mac.

3. Save your file as PDF/A

Aside from using optimised language and formatting, creating an accessible PDF technically means that the file is “tagged”. According to WebAim:

“PDF tags provide a hidden, structured representation of the PDF content that is presented to screen readers. They exist for accessibility purposes only and have no visible effect on the PDF file. There is more to an accessible PDF file than tags, but an untagged PDF would not be considered ‘accessible’.”

Tags can be added after the source document – i.e a Word file – has been created as it is being exported as a PDF. This can be done using the document’s software, or PDF software such as Acrobat.

  • If you’re using a Windows device with the latest version of Microsoft word installed, any document you save as a PDF should be a tagged document by default.
  • If you’re using a Mac, when you save a Word document as a PDF you should select ‘Best for electronic distribution and accessibility (uses Microsoft only Service’) before you export the document. If you do not see this option, the software you’re using does not support creating tagged PDF files.

Save an accessible PDF using Microsoft Office or find out more detail about saving documents as accessible PDF files on WebAim. You can also check how accessible your PDF is using Acrobat Pro, or try PAVE, an online PDF checker.

Turning a scanned document into a PDF

If you’re creating a PDF by scanning a paper document, use Optical Character Recognition (OCR) to make the PDF accessible to screen reader users. OCR is a software process which enables images of printed text to be translated into machine-readable text.

For University staff who use NitroPDF Pro (available through Apps Anywhere) to create PDF files, this option is available when you create a PDF from a scanned document.


  • Ensure any content within PDF files is accessible by using simple formatting and plain English.
  • Save documents using the PDF/A format.
  • Check your PDF is accessible by using a screen reader and Adobe Reader or Adobe Acrobat Pro.

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