> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/mui/base-ui/llms.txt
> Use this file to discover all available pages before exploring further.

# Collapsible

> API reference for the Collapsible component

# Collapsible

An interactive component that expands and collapses a panel.

## Import

```tsx theme={null}
import * as Collapsible from '@base-ui/react/collapsible';
```

## Collapsible.Root

Groups all parts of the collapsible.

### Props

<ParamField name="open" type="boolean">
  Whether the collapsible is currently open. To render an uncontrolled collapsible, use the `defaultOpen` prop instead.
</ParamField>

<ParamField name="defaultOpen" type="boolean" default="false">
  Whether the collapsible is initially open. To render a controlled collapsible, use the `open` prop instead.
</ParamField>

<ParamField name="onOpenChange" type="(open: boolean, eventDetails: Collapsible.Root.ChangeEventDetails) => void">
  Event handler called when the collapsible is opened or closed.
</ParamField>

<ParamField name="disabled" type="boolean" default="false">
  Whether the collapsible should ignore user interaction.
</ParamField>

## Collapsible.Trigger

The button that toggles the collapsible panel.

### Props

<ParamField name="nativeButton" type="boolean" default="true">
  Whether the component renders a native `<button>` element.
</ParamField>

## Collapsible.Panel

The content that can be collapsed.

### Props

<ParamField name="keepMounted" type="boolean" default="false">
  Whether to keep the panel mounted when collapsed.
</ParamField>

<ParamField name="hiddenUntilFound" type="boolean" default="false">
  Allows the browser's built-in page search to find and expand the panel contents.
</ParamField>