Text alternative does not include essential text in image
alt-text-essential-image-text
Rule
The alternative text for actionable images MUST be meaningful (accurately conveying the purpose or result of the action).
Background
People who are blind cannot see images on a page. In order to give people who cannot see an image access to the information conveyed by the image, it must have a text alternative. The text alternative must describe the information or function represented by the image. Screen readers can then use the alternative text to convey that information to the screen reader user.
For actionable or functional images - such as links or buttons - the alternative text must describe the destination, purpose, or function of the image - not necessarily the image itself. For example, the alternative text for an image that is a link or a button will describe the link destination or the button function, not the shape or other visual characteristics of the image.
How to Fix
Fix this issue by ensuring that the alternative text for the active image includes all essential text in the image so it accurately describes its destination, purpose, or function.
<a href="https://itunes.apple.com/us/app/xxxxxx.html"><img src="img/img-appstore-1rg.png" alt="Download on the App Store"></a>
<input type="image" src="magnify.png" alt="Search all courses">