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HTML class Attribute


Example

Use of the class attribute in an HTML document:

<html>
<head>
<style>
h1.intro {
  color: blue;
}

p.important {
  color: green;
}
</style>
</head>
<body>

<h1 class="intro">Header 1</h1>
<p>A paragraph.</p>
<p class="important">Note that this is an important paragraph. :)</p>

</body>
</html>
Try it Yourself »

More "Try it Yourself" examples below.


Definition and Usage

The class attribute specifies one or more class names for an element.

The class attribute is mostly used to point to a class in a style sheet. However, it can also be used by a JavaScript (via the HTML DOM) to make changes to HTML elements with a specified class.


Browser Support

Attribute
class Yes Yes Yes Yes Yes

Syntax

<element class="classname">

Attribute Values

Value Description
classname Specifies one or more class names for an element. To specify multiple classes, separate the class names with a space, e.g. <span class="left important">. This allows you to combine several CSS classes for one HTML element.

Naming rules:

  • Must begin with a letter A-Z or a-z
  • Can be followed by: letters (A-Za-z), digits (0-9), hyphens ("-"), and underscores ("_")

More Examples

Example

Add multiple classes to one HTML element:

<!DOCTYPE html>
<html>
<head>
<style>
h1.intro {
  color: blue;
  text-align: center;
}

.important {
  background-color: yellow;
}
</style>
</head>
<body>

<h1 class="intro important">Header 1</h1>
<p>A paragraph.</p>

</body>
</html>
Try it Yourself »

Example

Using JavaScript to add a yellow background color to the first element with class="example" (index 0).

let x = document.getElementsByClassName("example");
x[0].style.backgroundColor = "yellow";
Try it Yourself »

Example

Using JavaScript to add the "mystyle" class to an element with id="myDIV":

document.getElementById("myDIV").classList.add("mystyle");
Try it Yourself »

Related Pages

HTML Tutorial: HTML Attributes

CSS Tutorial: CSS Syntax

CSS Reference: CSS .class Selector

HTML DOM Reference: HTML DOM getElementsByClassName() Method

HTML DOM Reference: HTML DOM className Property

HTML DOM Reference: HTML DOM classList Property

HTML DOM Reference: HTML DOM Style Object


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