Active <area> elements must have alternate text
How to Fix the Problem
Ensure each clickable
<area> within an image map has an
aria-labelledby attribute value that describes the purpose of the
<img> elements with
usemap attribute values
identify image maps that use a set of
<map> tags enclosing
clickable hotspots defined by
area attribute values. An
alt attribute is required to define alternate text for
<img src="images/solar_system.jpg" alt="Solar System" width="472" height="800" usemap="#Map"/> <map name="Map"> <area shape="rect" coords="115,158,276,192" href="http://en.wikipedia.org/wiki/Mercury_%28planet%29" alt="Mercury"> <area shape="rect" coords="115,193,276,234" href="http://en.wikipedia.org/wiki/Venus" alt="Venus"> <!-- Remaining hotspots in image map... --> </map>
Don't use server-side image maps that rely on mouse click coordinates. These maps are not keyboard accessible, and do not provide text alternatives to the actionable areas of the image map.
<a href="/maps/nav.map"><img src="/images/navbar.gif" ismap></a>
Why it Matters
Screen readers have no way of translating images into words. It is important
that all images, including image maps, have
alt text values.
Screen readers typically announce the filename of the image if alternative text is missing. Filenames do not adequately describe images and are not helpful to screen reader users.
An image map is a single image with many clickable areas. Like all images, an image map must have alternate text for each of the different clickable areas, as well as for the larger image itself, since screen readers have no way of translating graphics into text.
The Algorithm (in simple terms)
area elements of image maps have alternate text.