HTML id Attribute
 HTML Standard Attributes
Example
Use the id attribute to change a text with a JavaScript:
<html>
<head>
<script type="text/javascript">
function change_header()
{
document.getElementById("myHeader").innerHTML="Nice day!";
}
</script>
</head>
<body>
<h1 id="myHeader">Hello World!</h1>
<button onclick="change_header()">Change text</button>
</body>
</html> |
Try it yourself »
(more examples at the bottom of this page)
|
Definition and Usage
The id attribute specifies a unique id for an HTML element.
The id must be unique within the HTML document.
The id attribute can be used by a JavaScript (via the HTML DOM) or by CSS to make changes or style the element with the specified id.
Support
W3C: The "W3C" column indicates whether or not the attribute is defined in the W3C HTML/XHTML recommendation.
| IE |
Firefox |
Opera |
Safari |
W3C |
| YES |
YES |
YES |
YES |
YES |
Syntax
Attribute Values
| Value |
Description |
| id |
Specifies a unique id for an 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 ("-"),
underscores ("_"), colons (":"), and periods (".")
- Values are case-sensitive
|
 |
Try it Yourself - Examples |
Add a unique
id to an HTML element
How to add the id attribute to an HTML element.
Use the
id attribute in CSS
How to use the id attribute in CSS.
HTML Standard Attributes
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