Read Image alt text and SVG titles first. Everything in that document also applies to charts and infographics. This document’s purpose is to extend that information.
Long description level of detail
The page must provide these users with the same level of information in text format.
For example, imagine a bar chart of sales data. The long description for the chart follows.
“Bar chart of units sold per store. Sales volumes that fell under the company target is shown in red.”
Based on that description, can you tell which months fell under the company goal? Or what the values were? Or what the company target is?
No. That description would fail 1.4.1 Use of Color.
A long description of the same chart that passes 1.4.1 Use of Color follows.
“Bar chart of units sold per store for Pennsylvania. Harrisburg 6,200, Philadelphia 9,900, Pittsburgh 2500. Sales that fell below the target of 7,000 units occurred in Harrisburg and Pittsburgh.”