When images are present in Web content, provide meaningful alternative text description so that users of screen readers can have the image described to them.

A good alt conveys what an image communicates, not what it contains. A picture of a child kicking a ball might have been selected because of the setting, the child, the kick or the ball, and the context determines the best description:

• Child happily kicking a ball on a summer day
• A.J. playing in the new team uniform
• A.J.'s game-winning kick curved in from the left sideline!
• The "medium" ball is the right size for this 9-year-old child

Best Practices

• Describe the image in context based on what details the image adds to the text.
• Keep the descriptions short and concise; roughly 140 characters or less.
• Do not use the word “graphic or image” in the description ("image of a running dog"), as the screen reader already takes care of it. Just say "a running dog."
• Use an empty alt (alt='"") for images with no visual meaning, like spacers or background textures, to tell screen readers you know what an alt attribute is, but you want them to not mention the image when reading the page.

If you need more than a sentence to describe the image, move the extra information into the visible text of the page. E.g., provide a table version of a chart, or a deep caption describing the complicated parts of the picture. This lets screen reader users explore the information in smaller chunks (by sentence or table cell), and also lets readers with low vision enjoy a text version of a graphic they may struggle to resolve.