Provide long descriptions for complex images
Overview
Some images are too complex to be briefly described by alt text. Complex images can include charts, graphs, artwork, maps, etc. These images need a longer description on the page that can go into more detail about the non-text content.
Best Practices
Include the long description on the same page as the visual. Depending on the complexity, many people might benefit from having a text-based version of the complex graphic.
The image alt text should describe a summary of the visual, as well as where the long description is on the page.
If possible, consider simplifying the image or graphic. If longer description is needed, chances are the visual could be confusing for people with varying learning, cognitive, or visual disabilities. Simplifying the visual will make your content more understandable and accessible.
Pattern Examples
In-page Description: Chart Example
The following image alt text is "Bar graph of assets in millions from 2012 to 2016. Described further under Details of Assets." After the image is the start of a more detailed description, under a Details of Assets heading.
Details of Assets
In 2012, assets started at $48.7 million, growing to $57.1 million the following year….
Map Example
One page might contain an embedded map, with text-based instructions above the embedded map.
Old Main Location
Old Main is located at 516 Main Street in Bellingham, WA. It is just north of Red Square and the Humanities building, and shares the Old Main front lawn with Wilson Library and Edens Hall.
Directions
[list directions for getting to building]
Long Descriptions for Artistic Images
How to describe a painting or other art depends on a few factors:
- What’s the purpose of using this artwork?
- Is it intended for users to interpret, or will the author interpret? If the users should come to their own interpretation, the description shout stick to what is visibly seen in the painting and not come to conclusions about its meaning.
Alt text: A painting by John Gast in 1872 titled American Progress, showing the spirit of America heading westward. See further details in the Description section.
Description
An 1872 painting by John Gast titled "American Progress" shows an expansive landscape with the sun rising in the upper right corner of the frame, behind faraway industrial East coast cities with their ships, bridges, and ports. Dramatic clouds fill the sky. The central landscape is rugged, flat, and open. Tall snow-capped mountains frame the painting in the upper left corner, opposite from the industrial cities on the right...(continue describing aspects of painting).”
Description borrowed from Deque University.