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The ASPIRE Guide to Accessible PDFs

Part 1: A User's Guide to Negotiating PDFs

Alistair McNaught

28 April 2021

PDFs are like Marmite – you love them or hate them. Sometimes you love them AND hate them at the same time. It’s wonderful to have a local version of something that you can read whether or not you have connectivity, but they are often an accessibility nightmare. University courses are full of PDFs with all kinds of flavours. One of the worst things is that there is no easy way of knowing what the accessibility is going to be like without manually testing it. This is a quick guide to what users SHOULD be able to do and how you might workaround any problems you encounter.

An icon of a jar of Marmite.
An icon of a PDF symbol.

1. Magnification with reflow

An icon featuring a magnifiying glass hovering over a document page, representing magnification and reflow.

Magnification is not helpful if it forces the end of the line off-screen. Accessible PDFs will reflow text when it is magnified, so that whatever magnification is chosen the text re-wraps to stay on screen.


If you open a PDF in the browser you can magnify using the normal browsing command, but it will not reflow. Don’t open it in the browser if you want significant magnification or if you want to turn a multi-column PDF into a single column layout.


Adobe Reader allows a high level of magnification. You turn on reflow manually with View > Zoom > Reflow. Sometimes it works. When it does it’s better than a Word document where you can only zoom to 500%. On Adobe Reader you can zoom to well over a thousand percent.

Unfortunately, it doesn’t always reflow when you switch on reflow. Sometimes it simply stays the same. Sometimes the spaces between all words disappear. Sometimes, on more complicated layouts, you get chaos with overlapping words and random letters. The worst of all is when it appears to work, but has actually hidden sentences or whole paragraphs under the page break. This can completely change the meaning of the text you are reading without you realising you’ve missed several paragraphs of the argument.


Adobe Digital Editions allows a maximum of 400% magnification and reflow is not possible.


Many PDFs can be opened in Microsoft Word. From here you can either use the web page view (View > Webpage) or the immersive reader (View > Immersive Reader) to get the magnification you need with the text reflowing.

2. Changing Background Colour

An icon of a stick figure painting a wall and holding a can of paint, representing changing background colour.

Many people find it more comfortable to read on a different background colour. Accessible PDFs will let you change the background.


It is not currently possible to change the background colour of the PDF you read in a browser.


The Edit > Preferences > Accessibility options in Adobe Reader allow you to select a huge range of background colours for the page.


It is not currently possible to change the background colour of PDFs you read in Adobe Digital Editions.


If you are able to open the document in Microsoft Word you can apply the huge range of background colours to the page. In Word it is also possible to change the font style and colour.

3. Navigation

An icon of a bookmack tag.
An icon of a navigation menu featuring 4 dots and 4 parallel horizontal bars

Many people can be overwhelmed by long PDFs but if the document has been created accessibly you should be able to easily find just the section you need by listing all the main headings and subheadings and clicking on the one most relevant to you.


In the browser look for a drop-down button. It’s usually labelled Contents (e.g. in Edge) or may appear in a collapsed menu on the menu bar in Chrome etc.


Look for the Bookmarks symbol in the left hand menu options. This should open up the Bookmarks panel which will allow you to navigate to any part of the document.


Click on the Reading menu and select Show Navigation Panel or look for the symbol on the menu bar.


Open the Navigation pane (View > Show > Navigation pane).

An icon of a document page with a speaker, representing text to speech.

4. Reading Out Loud


Microsoft Edge has built-in text-to-speech. When the PDF has been opened in Edge, right click over the PDF and select Read aloud.


Adobe Reader has built-in text-to-speech but it is very clunky, allowing you to either read an entire page or the entire document. It has very few options you can change, but if you wanted to use it (which we don’t really recommend) click View > Read out loud > Activate read out loud then click View > Read out loud and select whether to Read This Page Only or Read To End of Document.


Text-to-speech is not possible in Adobe Digital Editions.


Open the Immersive reader (View > Immersive Reader) and click Read aloud.


A left to right arrow, representing the output of the Word document to the PDF, and how this influences the accessibility of the PDF.
An icon of the Word document symbol, representing the original document created by the author.
An icon of a PDF symbol.
A left to right arrow, representing the output of the PDF.

There is always a dependency on the author's practice. If the author hasn’t used styles to create headings and subheadings, you won’t be able to navigate using any of the options above. If the author has created the document with a coloured background, you won’t be able to change the colour. If the author has grouped text and images alongside text, you won’t be able to magnify the text in a way that will reflow. If the PDF was created as a scanned image of text, text-to-speech will not work.

So none of the benefits outlined above can be guaranteed unless you know the PDF is coming from a source with good accessibility practices. If it is, then knowing the relative pros and cons of the different reading tools can make a huge difference to the ease with which you can get the precise reading ease and efficiency that you seek.


Alistair McNaught is one of the architects of the ASPIRE service and a long-term accessibility advocate. Learn more about the services of Alistair McNaught Consultancy. Follow Alistair on Twitter: @alistairm


If you would like to commission an ASPIREreview or have any questions or need help in creating your accessibility statement and telling your story, please contact us at

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