radiobutton

Radiobutton is a graphical control that allows the user to choose one option from a finite set. Each option is represented by a radio item, commonly illustrated as a small circle that becomes filled when selected. The items are grouped so that only one option can be active at a time; selecting a different option clears the previous selection.

In web forms, radios are input type="radio" elements. Radios that share the same name attribute belong to the same group; only one in that group can be checked. The value attribute of the checked input is submitted with the form. For accessibility, label each option with a label element and consider grouping the entire set with a fieldset and legend.

Users typically navigate with the keyboard: arrow keys move between options in the group; pressing Space or Enter selects the focused option. When an option is selected, others in the same group are automatically deselected. Disabled radios appear inactive and are not selectable.

Radios are appropriate when you need to present a small number of mutually exclusive choices. For longer lists or non-mutually exclusive choices, controls such as dropdown menus, list boxes, or separate controls may be more appropriate. In custom implementations, maintain accessibility by preserving the native semantics and using ARIA attributes where needed; ensure the control has an accessible label.