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.




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.


Specification Status Comment
HTML Living Standard
The definition of ':required' in that specification.
Living Standard No change.
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.
Proposed Recommendation Defines the pseudo-class, but not the associated semantics.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support10 Yes410105
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4.4.4 ? Yes4105 ?

See also

Document Tags and Contributors

Last updated by: mfuji09,