There may be more than one way to improve the accessibility of charts and graphs.
To create charts and graphs that people can easily understand, you need to know what you want your data to show, what your audience is looking for, and use extra help if needed to make your information clear.
Color choice is critical
For more information, please see our Color and Color Contrast training
Ensure all color choices meet contrast requirements, pay attention to how color represents information in your charts and graphics and don’t rely on color alone to convey information.
Color should be supplemental to your message, but not essential for understanding.
Avoid:
-
Green and red color combinations
-
Rainbow color maps
Color blind safe color pallets are available.
Add Patterns
When you add patterns to your graphics, it means you're not just relying on colors to convey information. Using patterns helps to make different sets of data stand out more, making it easier for people to understand.
Example 1.1: Bar chart with no pattern added.
This graphic currently relies on color to distinguish information. This makes it more difficult to determine the relationship with the legend.
Example 1.2: Bar chart WITH a pattern added.
If we add a pattern to each city’s information, we can better distinguish which bars represent which cities, making it easier to understand this bar graph.
Add Shapes
Similar to patterns, adding shapes to your charts builds additional distinction between data sets and relationships.
Example 2.1: Line graph without added shapes.
In this line chart, we are reliant on color to understand which city is which. This makes it difficult to determine the relationship between the line graph information and the legend.
Example 2.2: Line graph WITH added shapes.
By adding shapes to the line graph, we can easily determine which city relates to which line in our graphic. This new chart does not rely on color to understand the information.
Add Labels
Finally, you can always add labels to your charts. In this example, we have a pie chart showing a group of people’s favorite ice cream flavors.
Example 3.1: Pie chart without any labels. This chart relies entirely on color to show information.
This chart, again, relies on color to show users the data, is difficult to understand in relation to the legend, and is unable to give us numerical information.
Example 3.2: Pie chart WITH labels added for data. This chart is much easier to understand and does not use color alone. 
By adding labels, we no longer are relying on color, a legend isn't needed, and it is much easier to understand numerical data in relation to the data tracked.
Don't forget your alt text
For more information, please see our Images and Alt Text training
Alt text may not provide enough space to fully explain the information presented in your graphic, but it is still critical to add. Keep your alt text short and sweet (under 150 characters). Try to answer the questions:
-
What are the key findings?
-
Why is this chart important enough to add?
-
What do you want readers to understand from this graphic?
Example 4.1
alt=“Pie chart depicting five different favorite ice cream flavors. Rocky Road is the most favorite at 37.8%. Strawberry is the least favorite at 6.1%.”
Add Additional Content
Long Descriptions
If you can't fully describe your image using just alt text, you might need to include a longer description alongside it. This longer description should be in plain text and can be as detailed as necessary to explain the image to your audience. This usually works well as supplementary content for your chart or graph.
Example 5.1: This pie chart requires a long description to describe all of the information available in the chart.
This pie chart shows the favorite ice cream flavors of those surveyed. Respondents said that Rocky Road was their favorite ice cream at 37.8%, followed by Cookie Dough at 22.4%, Mint Chocolate Chip at 19.4%, Vanilla at 14.3%, and lastly with Strawberry at 6.1%.
Accessible Data Table
For more information, please see our Accessible Data Table training
You could also think about including an accessible data table with your chart to provide more detailed breakdowns of your data. For instance, in this example, we have a pie chart along with a data table that presents the same information in a more accessible format.
| Favorite Ice Cream Flavor | Percentage of Respondents |
| Rocky Road | 37.8% |
| Cookie Dough | 22.4% |
| Mint Chocolate Chip | 19.4% |
| Vanilla | 14.3% |
| Strawberry | 6.1% |
Additional Resources
Complex Images - W3C
Best Practices for Designing Accessible Views - Tableau
Color and Color Contrast
Colorblindly - Chrome Extension