The :required CSS pseudo-class represents any <input> element that has the required attribute set on it. This allows forms to easily indicate which fields must have valid data before the form can be submitted.

/* Selects <input> elements, but only if they */
/* have got required set on them */
input:required {
  border: 1px dashed red;
}

The :optional pseudo-class may be used to provide an appearance for optional form fields.

Syntax

:required

Examples

See :invalid for an example.

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 semantic regarding 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.
Candidate Recommendation Defines the pseudo-class, but not the associated semantic.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support 10.0 (Yes) 4.0 (2) 10 10.0 5.0
Feature Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 4.4.4 (Yes) 4.0 (2) No support 10.0 5.0

See also

Document Tags and Contributors

 Last updated by: mfluehr,