CSS Reference Manual

CSS @rules

Complete List of CSS Attributes

CSS Functions (Functions)Complete List of CSS Selectors

CSS :required selector

Online Example

If the input element is set to "required", set it to red:

Example

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">　
<title>Basic Tutorial(oldtoolbag.com)</title>　
<style>
input:required
{
　　　　background-color: red;
}
</style>
</head>
<body>
<h3>:required selector demonstration.</h3>
<p>Optional input elements：<br>　<input>　</p>
<p>Required input elements：<br>　<input　required>　</p>
<p>　:required selector selects form elements with the 'required' attribute.</p>
</body>
</html>

Test to see ‹/›

Definition and Usage

:required selector sets the specified style when the form element is a required field.

Form elements can use the required attribute to set required fields.

Note: 　:required selector is only applicable to form elements: input, select, and textarea.

Browser Compatibility

The numbers in the table indicate the first browser version that supports this attribute.

Selector
:required	10.0	10.0	4.0	5.0	10.0

CSS Selector :optional

Complete CSS Selector Reference Manual