Alt text should be a succinct description limited to 125 characters. For complex images, alt text may not be enough to fully explain the image. In these cases, a long description is required.
When a long description is required
Long descriptions must be used for images that contain:
- Detailed data (charts, graphs, tables)
- Flowcharts and diagrams that explain processes or sequences
- Text on the actual image
- Any important visual information that can’t be explained in 125 characters or less
What a long description should include
Long descriptions should:
- Fully describe the image
- Present details in a logical order (top to bottom, left to right)
- Include any text that appears inside the image
- Explain the relevant meaning of the image, not just its appearance (for example, “The chart shows an increase in enrollment from 2022 to 2025”)
Steps to insert a long description
- Upload or select an image.
- Update the alt text as you normally would in the program you’re using.
- If the program has a “long description” field, enter the full description there. If a long description field isn’t available, add the long description in one of the following ways:
- Include the description in the text near the image. This is the most effective approach, since text in the main content is easily accessed by screen readers.
- Add the description at the end of the document or in an appendix. If you use this approach, include a note in the main text directing readers to the appendix for more information about the image.
- Use a clear, descriptive caption for the image. If the program allows captions, the caption will display connected to the image.
- Save, update, or apply your changes, then review the content to confirm the long description was added correctly.
For more information, see the W3C Web Accessibility Initiative's Complex Images tutorial.
Still need help? Submit a Help Ticket to the Office of OneIT College Support at https://services.help.charlotte.edu/