How to make PDFs accessible

You must make sure your graph or chart is accessible, so no one misses out on important information.

How to make graphs and charts accessible in a PDF

If you include a graph or chart in your PDF, make sure it has: 

Text labels

Text labels help users interpret your graph or chart. All text labels must be horizontal, so they are easy to read. 

Your graph or chart must have the following visible text labels: 

• A title or caption - text positioned above the image that briefly describes what it shows. 
• Axis labels - if the graph or chart has axis, you must label them. For example, 'Percentage' and 'Area' in figure 1. 
• Series labels - to identify the types of data shown. For example, 'Low Skill', 'Medium Skill' and 'High Skill' in figure 1. 

Figure 1: Occupational profile for Norfolk, East of England, and England (2023). Source: Nomis - Official Census and Labour Market Statistics

Note: Power BI does not allow axis labels to be presented horizontally. If you copy Power BI visuals into your PDF, try to edit them to ensure axis labels are horizontal. 

Accessible colour coding

If you use colour coding in your graph or chart, you must include: 

• A legend/key - to explain what data each colour represents. This should include any shapes or patterns used too. See an example of this in figure 2. 
• A way for colour blind people to understand your graph or chart: 
  • Use data labels - horizontal, visible text. For example, 'Low Skill', 'Medium Skill' and 'High Skill' in figure 1; and/or 
  • Patterns - give each colour a unique pattern. For example, all four lines in figure 2 use a different shape that can be used to identify them. 

Figure 2: A line chart showing the average number of stem vegetables sold in the years 2020 to 2023

If you find it difficult to fit data labels that explain colour coding into your chart, try changing your chart orientation. 

For example, figure 3 shows how changing a vertical bar chart to a horizontal bar chart creates space for horizontal labels 'Norfolk', 'East of England' and 'England'. 

Good colour contrast 

You must make sure that any colour combinations you use have good contrast (stand out from each other): 

• Text must be a colour that's easy to see against the background colour. For example, the 'England' white text stands out well against the dark blue segment colour in figure 3. 
• Coloured segments must contrast well with the page background colour and any other coloured segments they are next to. For example, the maroon coloured segments contrast well with the white page background and the turquoise segments in figure 3. 

Figure 3: Percentage of pupils meeting the expected standard in reading, writing, and maths (combined). Source: Nomis - Official Census and Labour Market Statistics

For more information on colour contrast and how to test it, go to our colour contrast page. 

If you find it difficult to find colours to use that contrast well with each other and the page background: 

• Use one of the Office for National Statistic's accessible colour palettes; or 
• Separate coloured segments so they don't touch each other. Then you only need to make sure that each coloured segment contrasts well with the page background. 

Be aware that many PDF built-in graph and chart colour themes do not meet colour accessibility requirements - so check them before you use them. 

A text description 

You must provide a text description for your graph or chart. This is a text version of the information the graph or chart shows. It helps make sure people who can't see the image or find it difficult to interpret don't miss out on any information. 

The text description should describe your graph or chart and the key information it shows. This could include a paragraph that describes overall trends the graph or chart shows, or all the data shown in table format.  

To provide a text description, follow the advice in the 'How to provide a text description' section on our images accessibility page.

Accessible image formatting

You must format your graph or chart as a single, flat image. To do this you might need to: 

• Copy the graph/chart and paste it as an image (Microsoft Support website); or 
• Save the graph/chart as an image, then insert it into your PDF; or 
• Take a screenshot of the graph/chart, then paste or insert it into your PDF 

You must also make sure the image is good quality, so it remains clear and easy to use when a user zooms in up to 400%. 

How to make graphs and charts accessible

If you find that any graphs or charts in your PDF aren't accessible, you must fix them.

Edit the source document

Most PDFs on our websites were created in Word originally. The easiest way to make graphs and charts in your PDF accessible is to edit the source document (eg Word), and then reconvert it to a PDF.

If you need to go back to your original Word document:

• For help formatting your graph or chart as a single, flat image, go to our advice on how to make graphs and charts accessible in Word
• For help providing a text description for your graph or chart, go to the 'How to provide a text description' section in our advice on how to make images accessible in Word

You may find our Word accessibility advice useful even if you used a different application to create your PDF.

Edit the PDF

Visit our PDF images accessibility page to find out how to provide a text description in a PDF using Adobe Acrobat Pro.