Descriptive images need text equivalents in order to be accessible. Text equivalents (also called "alt text") are phrases or sentences that describe an image's visual appearance and provide any additional useful information. Depending on the audience and the author's motivation for using an image, the text equivalents may also describe what the reader is expected to learn from the image, instructions on how to take action (such as clicking an arrow image to navigate through online help), or how the image relates to the adjacent text.
All descriptive images should include descriptive text equivalents that represent the meaning of the visual item. Meaningful text equivalents can be written only by the author or someone else intimately familiar with the material and intent.
Benefits to Users & Developers
- Establishes context, provides visual interest, and assists with navigation.
- Provides visual information in a non-graphical environment.
- Allows assistive devices users, such as screen readers or refreshable Braille, to understand non-text items.
- Provides additional information to all readers, whether or not they have disabilities.