Definition and Usage
The :optional CSS pseudo-class represents any <input> element that does not have the required attribute set on it. This allows forms to easily indicate optional fields, and to style them accordingly.
To provide an appearance for required form fields, the :required pseudo-class may be used.
Examples
See :invalid for an example.
Compatibility
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 |