Radio buttons are used for selection of only one option from a group of values.
Each radio button group requires a minimum of 2 options to choose from.
Use a Select component if there are more than 6 options to choose from.
Only one option within a radio button group may be selected at one time, and one must be selected by the user (otherwise don't use radio buttons).
Although one of the options in a radio button group may be selected by default, it's recommended that none of them be selected by default so that users are more aware of the decision. Setting a default value can also discourage users from making conscious decisions, seem pushy, or alienate users who don’t fit into your assumptions.
Some radio button options may begin disabled until selections are made elsewhere on the page, while others may become disabled as the result of selections elsewhere. In such cases, the corresponding selection should be in view at the same time as the radio button group.
Radio buttons that are listed vertically are easier to read than those that are listed horizontally. Horizontal listings can make it difficult to tell which label pertains to which radio button.
Selecting a radio button should not trigger unexpected changes in context, such as causing significant changes to the page content or opening a new window
A form validation checks user input against success criteria before passing the data to the server. If there is a problem with the data then the system generates an error to help the user complete their task. An error notification is displayed at top of page, and any radio button groups that are in error are visually indicated.
Title case, 2-3 words maximum.
Do not combine actions in a label (exception: "Customize & Buy").
If standard labels don't fit the button's purpose, align label with the task the user is attempting.
Please refer to the Dell Technologies branding website, https://brand.delltechnologies.com/faq/#voice, for further information regarding call-to-action labels and usage.
The A11Y Style Guide has excellent examples of markup for radio buttons.
The W3C Web Accessibility Initiative (WAI) develops standards and support materials to help you understand and implement accessibility.
Please follow the best practices for a radio group from WAI-ARIA authoring practices 1.1.
Please also refer to these recommendations for a radiogroup from WAI-ARIA 1.1.
You may also refer to these tutorials for form concepts from Web Accessibility Tutorials.
You may also refer to this article about creating accessible forms from WebAIM.