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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

See :invalid for an example.

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 Standard
The definition of ':required' in that specification.
Living Standard No change.
HTML5
The definition of ':required' in that specification.
Recommendation Defines the semantics of HTML and constraint validation.
Selectors Level 4
The definition of ':required' in that specification.
Working Draft No change.
CSS Basic User Interface Module Level 3
The definition of ':required' in that specification.
Recommendation Defines the pseudo-class, but not the associated semantics.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
:requiredChrome Full support 10Edge Full support YesFirefox Full support 4IE Full support 10Opera Full support 10Safari Full support 5WebView Android Full support 4.4.3Chrome Android ? Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support 10Safari iOS Full support 5Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also

文件標籤與貢獻者

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