HTML id Attribute
Example
Use the id attribute to manipulate text with JavaScript:
<html>
<body>
<h1 id="myHeader">Hello World!</h1>
<button onclick="displayResult()">Change text</button>
<script>
function displayResult()
{
document.getElementById("myHeader").innerHTML = "Have a nice day!";
}
</script>
</body>
</html>
Try it Yourself »
More "Try it Yourself" examples below.
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.
Browser Support
| Attribute | |||||
|---|---|---|---|---|---|
| id | Yes | Yes | Yes | Yes | Yes |
Differences Between HTML 4.01 and HTML5
In HTML5, the id attribute can be used on any HTML element (it will validate on any HTML element. However, it is not necessarily useful).
In HTML 4.01, the id attribute cannot be used with: <base>, <head>, <html>, <meta>, <param>, <script>, <style>, and <title>.
Note: HTML 4.01 has greater restrictions on the content of id values (for example; in HTML 4.01, id values cannot start with a number).
Syntax
<element id="id">
Attribute Values
| Value | Description |
|---|---|
| id | Specifies a unique id for the element.
Naming rules:
|
More Examples
Example 1
Use the id attribute to link to an element with a specified id within a page:
<html>
<body>
<h2><a id="top">Some heading</a></h2>
<p>Lots of text....</p>
<p>Lots of text....</p>
<p>Lots of text....</p>
<a href="#top">Go to top</a>
</body>
</html>
Try it Yourself »
Example 2
Use the id attribute to style text with CSS:
<html>
<head>
<style>
#myHeader {
color: red;
text-align: center;
}
</style>
</head>
<body>
<h1 id="myHeader">W3Schools is the best!</h1>
</body>
</html>
Try it Yourself »
Related Pages
HTML Tutorial: HTML id
HTML Tutorial: HTML Attributes
CSS Tutorial: CSS Syntax
CSS Reference: CSS #id Selector
HTML DOM Reference: HTML DOM getElementById() Method
HTML DOM Reference: HTML DOM id Property
HTML DOM Reference: HTML DOM Style Object
