Alternative text for images

Screen shot of add image modal in the editorThe alt attribute (Alt Text) is used to provide an alternative to the image for users who can’t see it. The possible alternatives to any image can be highly diverse, depending on the usage and context of that image.

On the Web Accessibility Tutorials of the W3C there’s a great Alt Decision Tree tool that describes how to use the alt attribute  of an image in various situations.

Note: If you use an image as link, the important information about the image is not what’s depicted. Instead, it’s the target of the link, since that’s what users need to know about. Use text that indicates the target of the link, such as the title of the targeted post.