HTML Area Alt Attribute

The alt attribute is a vital component in web development, particularly for accessibility. This article will explore the HTML area alt attribute, how it is used, and when to apply it effectively. By the end, you will have a solid understanding of the importance of the alt attribute especially within map elements.

What is the alt Attribute?

The alt attribute is a means to provide alternative text for images and areas of image maps in HTML. This can improve accessibility for users who rely on screen readers as well as provide context when images do not load. The text within this attribute gets displayed when the respective image or area cannot be rendered. It serves as descriptive text that helps users understand what the image represents.

The alt Attribute in HTML

In HTML, the alt attribute is primarily used within the tag and

tag. Its purpose is to ensure that all users, including those with disabilities, have an understanding of the content.

Usage with Tag

<img src="example.jpg" alt="A beautiful sunset over the mountains">

Usage with

Tag

The area tag is used within a map element to define clickable regions. Each

can have an alt attribute to describe its purpose or content.

<map name="example-map">
  <area shape="rect" coords="34,44,270,350" href="sunset.html" alt="A sunset view" title="Sunset">
  <area shape="circle" coords="400,200,100" href="nature.html" alt="Nature scenery" title="Nature">
</map>

When to Use the alt Attribute?

The alt attribute should be used under the following circumstances:

• When you have images that convey information. Providing alternative text helps users understand the context and meaning of the image.
• For images that are links. Describing the link’s purpose through the alt attribute increases usability.
• In image maps. Each
  within a

• When the image is purely decorative, an empty alt attribute <code>alt=””</code> is recommended to inform screen readers to ignore it.

Example of the alt Attribute

Below is an example of using the alt attribute effectively within an image map:

<img src="world-map.jpg" alt="A world map" usemap="#worldmap">

<map name="worldmap">
  <area shape="rect" coords="34,44,270,350" href="usa.html" alt="USA" title="United States">
  <area shape="circle" coords="400,200,100" href="canada.html" alt="Canada" title="Canada">
  <area shape="poly" coords="150,120,150,210,60,150" href="mexico.html" alt="Mexico" title="Mexico">
</map>

In this example, we have a world map, and the corresponding map areas are highlighted. Each area has a descriptive alt attribute that provides context about the region.

Related Attributes

Here are some related attributes that complement the use of the alt attribute in HTML:

Attribute	Description
title	The title attribute provides additional information about an element, typically displayed as a tooltip when hovered over.
longdesc	The longdesc attribute provides a link to a detailed description of the image, often for complex images requiring more context.
href	The href attribute specifies the URL that the linked resource points to, relevant in link and area tags.
target	The target attribute defines where to open the linked document, influencing how users interact with links.

FAQ Section

What happens if I don’t use the alt attribute?

If the alt attribute is not used, screen readers will be unable to convey any information about the image to users, leading to a poor experience for those with visual impairments. Additionally, if an image fails to load, users won’t receive contextual information.

Is there a difference between alt text for images and areas in image maps?

Yes, while the purpose of the alt attribute remains the same—to provide descriptive text—the context differs. For images, it describes the content of the image. For areas in image maps, it explains what the clickable region or the link represents.

Can I use empty alt attributes?

Yes, using empty alt attributes (i.e., alt="") is recommended for decorative images that do not add meaningful content. This informs screen readers to skip over the images.

Are there any limitations to the alt attribute?

The alt attribute does not support rich text formatting or HTML markup within its value and should be concise, typically around 125 characters maximum for effectiveness.

How can I ensure my alt text is effective?

To create effective alt text, be descriptive yet concise. Focus on the function and context of the image or area. Avoid phrases like “image of” or “picture of” as it is already understood that it refers to an image.