Radio Buttons are used when the user must select exactly one choice. If the user needs to select any number of choices (zero, one or several) use Checkboxes instead.¹

Use Radio Buttons over Dropdown Selects where space permits. This allows all options to be visible to the user, who can easily compare them.¹

Have a default Radio Button option selected whenever possible. A default choice is a strong suggestion to the user that helps them make their decision and increases their confidence in the app. When the frequently selected choice is set to be the default, it helps users expedite their tasks. If users need to refrain from making a selection, you should provide a radio button labeled “None.” Use analytics to help determine what our users commonly select.²

Use the component disabled state. Don’t change the opacity to indicate a disabled state. ³