A long description is a way to provide long alternative text for non-text elements, such as images. Generally, alternative text exceeding 125 characters, which cannot be made more concise without making it less descriptive or meaningful, should have a long description.
The objective of this technique is to provide a long text alternative that serves the same purpose and presents the same information as the original non-text content when a short text alternative is not sufficient.
Combined with the short text alternative, the long description should be able to substitute for the non-text content.
Alternative text is not enough
Alternative text is not enough
This infographic violates several criteria:
- Insufficient color contrast of the presented information
- Text on images can not be adapted (scalable and color change)
- 400% zoom in not possible without loosing context
Example
Example
Alternative text : “73,000 employees working in 50 countries and representing 145 nationalities - find long description below.”
Example
Example
How to use it
How to use it
- The best solution is to include the additional information in an "Expandable box component" (see example).
- A good solution is also to include the complete description of the image in the content of the page, immediately before or after the image and to indicate in the alt text.
- An alternative is to create another web page with just the long description of the infographic and link to it (in a lightbox) directly after the image.
We recommend the following basic structure for the long description page:
- Title
- Construction of the graph
- Summary
- Data table
Crosslinks
