Provide a text-based equivalent for every viz.
Providing a text summary of your data visualizations will allow non-visual users to understand the key findings from the visualization. What is important about the data? What are the key trends or main takeaways?
Ideally, every data visualization should have a text-based equivalent. If this is not possible, the data presented in the visual should at a minimum be summarized in an accessible table. Adding a text summary will benefit any users that find the visualization confusing and can also improve the search rankings for your content.