Web/CSS/ required

The :required CSS pseudo-class represents any <input>, <select>, or <textarea> element that has the required attribute set on it.

/* Selects any required <input> */
input:required {
  border: 1px dashed red;
}

This pseudo-class is useful for highlighting fields that must have valid data before a form can be submitted.

Note: The :optional pseudo-class selects optional form fields.

Syntax

:required

Examples

The required field has a red border

HTML

<form>
  <div class="field">
    <label for="url_input">Enter a URL:</label>
    <input type="url" id="url_input">
  </div>

  <div class="field">
    <label for="email_input">Enter an email address:</label>
    <input type="email" id="email_input" required>
  </div>
</form>

CSS

label {
  display: block;
  margin: 1px;  
  padding: 1px;
}

.field {
  margin: 1px;
  padding: 1px;
}
 
input:required {
  border-color: #800000;
  border-width: 3px;
}

input:required:invalid {
  border-color: #c00000;
}

Result

Accessibility concerns

Mandatory <input>s should have the required attribute applied to them. This will ensure that people navigating with the aid of assistive technology such as a screen reader will be able to understand which inputs need valid content to ensure a successful submission.

If the form also contains optional inputs, required inputs should be indicated visually using a treatment that does not rely solely on color to convey meaning. Typically, descriptive text and/or an icon are used.

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of ':required' in that specification.	Living Standard	No change.
HTML5The definition of ':required' in that specification.	Recommendation	Defines the semantics of HTML and constraint validation.
Selectors Level 4The definition of ':required' in that specification.	Working Draft	No change.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`:required`	Chrome Full support 10	Edge Full support 12	Firefox Full support 4	IE Full support 10	Opera Full support 10	Safari Full support 5	WebView Android Full support 4.4.3	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 5	Samsung Internet Android Full support 1.0

Legend

Full support: Full support