How to ensure the accessibility of interactive charts and graphs for screen reader users?

Visual data, such as charts, graphs, and maps, presents a major challenge for users with visual impairments because they rely exclusively on the visual perception of information. To make such content accessible, developers need to apply a comprehensive approach combining alternative text, text tables, and interactive text descriptions.

The first step is to provide a brief description of the general trend or key takeaway illustrated by the chart using aria-label or aria-describedby attributes directly on the element's container. This allows screen reader users to immediately understand the main idea without having to examine every data point individually.

The second important aspect is duplicating visual information as an accessible data table, placed next to the chart or visually hidden using CSS for users without visual impairments while remaining available to assistive technologies. The table must have a clear header structure with th tags and the scope attribute so the screen reader can correctly announce relationships between cells.

For complex interactive charts, it is useful to create step-by-step keyboard navigation through data elements. The user should be able to switch between columns or chart points using the arrow keys, while the screen reader announces the value of a specific point and its category. This turns a static visualization into a fully functional accessible data analysis tool.