Stable in React

Form

A native form element with consolidated error handling.

Loading React 19.3.1…

Hover a part or use it. The code follows. · Loading React…

100Tests passing in React · 0 failing

3.1 KiBSize

Not measured yetMemory

Not measured yetSpeed

productdevbook and 9 upstream authors11 commits · last Nov 3

Install#

One package per framework. Form's parts come from it; the anatomy tab at the top shows how they nest.

bun add @▢▢▢▢/react

One part. The example uses one of them; the data does not say which are required.

FormA native form element with consolidated error handling.

Examples#

Common ways to put it to work. Each one runs live.

The form submits through a server function with the action state.

FormAction.tsx

Styling and accessibility#

The parts ship no styles. Style their states with these attributes; the CSS tab at the top has a sheet. The same CSS works in all five frameworks.

Form has no data attributes or CSS variables.

Keyboard

Form adds no keys; Enter in a field submits it, as a native form does.

Set for you

renders a <form>the browser's own submit, reset and autofill workForm
moves focus to the first invalid field when a submit failsthe person lands on the error to fixForm
hands each entry of errors to the field with the same namea server's error is read with its field, not elsewhere on the pageForm

API reference#

4 props across 1 parts, in React syntax, and className, style, render once for every part. Open a row to try it.

Filter props

Form · all parts

Shared propsEvery part that renders an element takes these.

classNameCSS class applied to the element, or a function that returns a class based on the component's state.string | ((state: State) => string | undefined)

styleStyle applied to the element, or a function that returns a style object based on the component's state.React.CSSProperties | ((state: State) => React.CSSProperties | undefined)

renderAllows you to replace the component's HTML element with a different tag, or compose it with another component.

React.ReactElement<unknown, string | React.JSXElementConstructor<any>> | ComponentRenderFn<React.DetailedHTMLProps<React.FormHTMLAttributes<HTMLFormElement>, HTMLFormElement>, State>

Use it in React#

What differs from the React API. Switch the framework at the top of the page.

@▢▢▢▢/react is the React 19 package. Its parts, props, data attributes and error messages are upstream Base UI's, and upstream's own tests run against it.

Parts
Each component is its own entry point and exports one namespace named after it.
```
import { Switch } from '@base-ui-next/react/switch'

export function Example() {
  return (
    <Switch.Root>
      <Switch.Thumb />
    </Switch.Root>
  )
}
```
A part renders the element its API reference names, such as a <span> for Switch.Root.
Props and events
Props and callbacks have upstream's names and signatures: onCheckedChange(checked, details), onOpenChange(open, details), onValueChange(value, details). details carries reason, event, cancel() and allowPropagation(). Native handlers are React's (onClick, onKeyDown), and event.preventBaseUIHandler() stops a part's own handler.
Styling
className takes a string or a function (state) => string; style takes an object or a function (state) => object. The state's data-* attributes are on the element for CSS.
render
render takes an element (render={<a href="/docs" />}) or a function (props, state) => element that spreads props on what it returns.
Refs
ref reaches the part's element. Imperative handles are ref props, as upstream: inputRef, and actionsRef ({ validate } on Field and Form, { unmount, close } on Dialog).
Binding
A part is controlled when its value prop (checked, open, value) is set, and uncontrolled with the default form (defaultChecked, defaultOpen, defaultValue). React has no two-way binding: pair the value with its change callback.
From @base-ui/react
Change the import from @base-ui/react/<component> to @▢▢▢▢/react/<component>.
From @base-ui/react
Nothing else changes: props, parts, data attributes and errors are the same.