:required

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.

Syntax

:required { style properties }

Examples

See :invalid for an example.

Specifications

Specification	Status	Comment
WHATWG 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

See also

• :optional, :invalid, :valid