...
HTML Publish in HTML format wherever possible. HTML documents are:
- are easier to find in search engines
- easier to read online because they reformat to fit mobile devices
- easier to keep up to date
- are readable by a wide range of assistive technologies used by people with disabilities
PDF documents:
- can make content harder to find in search engines
- are harder to keep up to date
- do not work well with assistive technologies like screen readers
...
Colour Do not use colour or shape alone to convey meaning.
Graphs
- do not rely on colour alone to convey information
- use different line styles or types of shading to differentiate between lines or bars
- attach the meaning of bars or lines to the bars or lines themselves, rather than in a separate legend
Read our guide to Accessible charts and graphs for examples of best practice.
Alternative text If you’re using images or charts, think how you’ll make the content accessible to people with a visual impairment.
...
Images with text Do not use images containing text, as it’s not possible to resize the text in the image and screen readers cannot read text which is part of an image.
InfogramsInfographics Many visually impaired people use screen magnifiers. This means they cannot see the overall design of an infogram infographic and makes it hard difficult to understand the relationships between visual elements and the information conveyed by the layout and design. Also, most screen readers cannot read text which is embedded in an image.
Therefore, if you're including an infograminfographic in a page, make sure all the important information it conveys is also in the main text.
...
Government Digital Service (GDS) accessibility accessible document guidelines: