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

# Collapsible

> A single inline expandable block that shows or hides content when triggered. Use when one section of a page needs to toggle independently of other sections.

## Collapsible

<Badge color="blue">v1.0.0</Badge> | [View in Storybook](https://master--695bb4b1b8041ae09768950a.chromatic.com/?path=/docs/primitives-collapsible--docs)

### When to use

* A mutually exclusive optional or secondary block of content on a page (e.g. AI reasoning, advanced settings, an explanation, a preview).
* When the content is useful but not essential to the primary task.

### When to use something else

* Multiple stacked expandable sections: use [Accordion](/aura-design-system/primitives/accordion) instead.
* Navigation or filtering: use [Tabs](/aura-design-system/primitives/tabs) or filter controls ([Combobox](/aura-design-system/primitives/combobox), [Select](/aura-design-system/primitives/select), etc.).
* Content the user almost always needs: show it by default—don’t hide it in a collapsible.

### Dos and don'ts

* Do default to collapsed unless the collapsible content is the main purpose of the view.
* Do keep the trigger label descriptive — it should communicate what's inside, not just say "more".
* Don't nest Collapsibles — if you need layered disclosure, reconsider the information architecture.
* Don't use it to hide errors or required information.

### Behavior

* One trigger expands or collapses a single associated region; animation is optional but state (expanded/collapsed) must be exposed to assistive tech when it conveys meaning.
* Do not nest collapsibles; use [Accordion](/aura-design-system/primitives/accordion) for multiple independent sections.

### Often used with

* Clear trigger (button or link styled per system); [Separator](/aura-design-system/primitives/separator) when stacking multiple collapsible regions on one page.