[role="img"] elements must have an alternative text
How to Fix the Problem
Correct markup solutions
The following four markup examples all pass because each example contains markup rendered as alternative text:
<div id="match">Bananas</div>
<div role="img" aria-labelledby="match" id="pass2"></div>
<div id="hidden-match" style="display:none">Banana bombs</div>
<div role="img" aria-labelledby="hidden-match" id="pass3"></div>
<div role="img" aria-label="blah" id="pass1"></div>
<div role="img" title="title" id="pass4"></div>
Incorrect markup solutions
The following five examples fail the role-img-alt
rule because
the markup contains no corresponding and meaningful alternative text:
<div role="img" id="violation1"></div>
<div role="img" aria-label="" id="violation2"></div>
<div role="img" alt="blah" id="violation3"></div>
<div role="img" aria-labelledby="no-match" id="violation4"></div>
<div role="img" title="" id="violation5"></div>
Why it Matters
Screen readers have no way of translating an image into words that gets read to the user, even if the image only consists of text. As a result, it's necessary for images to have short, descriptive and accessible alternative text so screen reader users clearly understand the image's contents and purpose.
If you can't see, all types of visual information, including images, are completely useless unless an accessible text alternative is provided which screen readers can convert into either sound or braille. People with low vision or color-blindness disabilities also require accessible alternative text to varying degrees.
Screen readers cannot convert visual image information to speech or braille in the absence of an accessible text alternative associated with the image.
Rule Description
Ensures elements marked role="img"
elements have alternate text.
The Algorithm (in simple terms)
Elements with the role="img"
attribute value must also contain
markup specifying accessible alternative text describing the image.