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HTML id Attribute

HTML Standard Attributes Reference HTML Standard Attributes

Example

Use the id attribute to manipulate text with JavaScript:

<html>
<head>
<script type="text/javascript">
function displayResult()
{
document.getElementById("myHeader").innerHTML="Have a nice day!";
}
</script>
</head>

<body>
<h1 id="myHeader">Hello World!</h1>
<button onclick="displayResult()">Change text</button>
</body>

</html>

Try it yourself »
(more examples at the bottom of this page)

Browser Support

Internet Explorer Firefox Opera Google Chrome Safari

The id attribute is supported in all major browsers.

Definition and Usage

The id attribute specifies a unique id for an HTML element (the value must be unique within the HTML document).

The id attribute is most used to point to a style in a style sheet, and by JavaScript (via the HTML DOM) to manipulate the element with the specific id.

Tips and Notes

Note: The id attribute is not valid in: <base>, <head>, <html>, <meta>, <param>, <script>, <style>, and <title>.

Syntax

<element id="id">

Attribute Values

Value Description
id Specifies a unique id for the 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 ("_")
  • In HTML, all values are case-insensitive

Examples

Try it Yourself - Examples

Add an id attribute to an HTML element, and use it in CSS
Use the id attribute to style text with CSS.

HTML Standard Attributes Reference HTML Standard Attributes
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