Radio

Status: Experimental

Radio preserves a native radio input and makes its visible label the full activation target. Frasto uses a square boundary and inner square selection mark instead of circular geometry.

Preview

Billing cadence

MonthlyAnnual

Basic usage

---
import { Radio } from '@freightpx/frasto';
---

<fieldset>
  <legend>Billing cadence</legend>
  <Radio name="cadence" value="monthly" checked>Monthly</Radio>
  <Radio name="cadence" value="annual">Annual</Radio>
</fieldset>

Radios with the same name form one native selection group. Give each option a distinct value.

Selection behavior

Only one enabled radio in a named group can be selected. Selecting a different option clears the previous selection automatically through native browser behavior.

Use Checkbox when each option can be selected independently. Do not use radios for a single yes-or-no choice.

Sizes

Small · 16pxDefault · 18px

Use sm in dense filters and compact option matrices. Use md for ordinary forms and settings.

Invalid and disabled

Required optionUnavailable optionSelected but unavailable

invalid applies the danger border and aria-invalid="true". Prefer marking and describing the group as a whole when the validation problem applies to every option.

API

Prop	Type	Default	Purpose
size	'sm' | 'md'	'md'	radio and label size
checked	boolean	false	initial selected state
disabled	boolean	false	removes an option from interaction and submission
invalid	boolean	false	danger treatment and invalid semantics
class	string	—	adds a class to the outer label
inputClass	string	—	adds a class to the native input

Native input attributes, including name, value, required, and aria-*, are forwarded.

Accessibility

• Wrap a related radio group in fieldset and give it a concise legend.
• Use one shared name for all options in a group.
• Keep option labels distinct and understandable without relying on their position.
• The default slot supplies the accessible label. If omitted, provide aria-label or aria-labelledby.
• Put shared help and error text on the group and associate it appropriately.
• Native arrow-key behavior moves between enabled options in the group.

Responsive behavior

The square control remains fixed-size while labels wrap naturally. Groups may change from horizontal to vertical layout without changing radio semantics or names.