required property CSS Reference

Definition and Usage

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.

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


See :invalid for an example.


Desktop browsers

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 10.0 4.0 (2) 10 10.0 5.0

Mobile browsers

Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support NA 4.0 (2) Not supported 10.0 5.0

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