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<!--> <!DOCTYPE> <a> <abbr> <acronym> <address> <applet> <area> <article> <aside> <audio> <b> <base> <basefont> <bdi> <bdo> <big> <blockquote> <body> <br> <button> <canvas> <caption> <center> <cite> <code> <col> <colgroup> <command> <datalist> <dd> <del> <details> <dfn> <dialog> <dir> <div> <dl> <dt> <em> <embed> <fieldset> <figcaption> <figure> <font> <footer> <form> <frame> <frameset> <head> <header> <hgroup> <h1> - <h6> <hr> <html> <i> <iframe> <img> <input> <ins> <kbd> <keygen> <label> <legend> <li> <link> <map> <mark> <menu> <meta> <meter> <nav> <noframes> <noscript> <object> <ol> <optgroup> <option> <output> <p> <param> <pre> <progress> <q> <rp> <rt> <ruby> <s> <samp> <script> <section> <select> <small> <source> <span> <strike> <strong> <style> <sub> <summary> <sup> <table> <tbody> <td> <textarea> <tfoot> <th> <thead> <time> <title> <tr> <track> <tt> <u> <ul> <var> <video> <wbr>HTML id Attribute
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>
<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
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.
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:
|
 |
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 Global Attributes
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