Active <area > elements must have alternate text

Rule ID: area-alt
User Impact: Critical
WCAG: 1.1.1, 2.4.4, 4.1.2

Compliance Data & Impact

User Impact

Disabilities Affected

  • Blind
  • Deafblind
  • Mobility

Requirement(s)

  • Section 508: MUST

WCAG Success Criteria

  • 1.1.1 Non-text Content
  • 2.4.4 Link Purpose (In Context)
  • 4.1.2 Name, Role, Value

Section 508 Guidelines

  • 1194.22 (a) Text equivalent for non-text elements

Rule Description

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.

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.

How to Fix the Problem

Ensure each clickable <area> within an image map has an alt, aria-label or aria-labelledby attribute value that describes the purpose of the link.

<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 additional alt attribute is required to define alternate text for each area:

<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>

Bad Example

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>

The Algorithm (in simple terms)

Ensures area elements of image maps have alternate text.