Alternate Text

Provide alternative text for images

Individuals with visual problems or other cognitive impairments are unable to comprehend information communicated through visuals without the assistance of a textual equivalent. Charts, graphs, and other non-textual content are examples of image-based content that is  accessible.

Images are accompanied by textual equivalents to make the information and intent of the images more accessible. Screen-reading software must be compatible with all alternatives.

The alt attribute on the <img> and <input type="image"> tags provides alternative text for images on web pages.

 

Guidelines

The usage of alternative text should be guided by the following considerations:

  1. If the image is required for comprehending the page's content, the alt attribute should be used to express similar information in the text.
  2. If the image is purely aesthetic and has no bearing on the page's content, the alt attribute should be left blank (alt=""). Empty characteristics instruct screen-reading software to ignore the image entirely.
  3. If an image is used as a button or inside a link, the alternative text should describe the  button's purpose.