---
layout: docs
title: Collapse
group: components
---
The Bootstrap collapse plugin allows you to toggle content on your pages with a bit of JavaScript and some classes. Flexible plugin that utilizes a handful of classes (from the **required [transitions plugin]({{ site.baseurl }}/components/transitions/)**) for easy toggle behavior.
## Contents
* Will be replaced with the ToC, excluding the "Contents" header
{:toc}
## Example
Click the buttons below to show and hide another element via class changes:
- `.collapse` hides content
- `.collapsing` is applied during transitions
- `.collapse.in` shows content
You can use a link with the `href` attribute, or a button with the `data-target` attribute. In both cases, the `data-toggle="collapse"` is required.
{% example html %}
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.
{% endexample %}
## Accordion example
Extend the default collapse behavior to create an accordion.
{% example html %}
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
{% endexample %}
## Accessibility
Be sure to add `aria-expanded` to the control element. This attribute explicitly defines the current state of the collapsible element to screen readers and similar assistive technologies. If the collapsible element is closed by default, it should have a value of `aria-expanded="false"`. If you've set the collapsible element to be open by default using the `in` class, set `aria-expanded="true"` on the control instead. The plugin will automatically toggle this attribute based on whether or not the collapsible element has been opened or closed.
Additionally, if your control element is targeting a single collapsible element – i.e. the `data-target` attribute is pointing to an `id` selector – you may add an additional `aria-controls` attribute to the control element, containing the `id` of the collapsible element. Modern screen readers and similar assistive technologies make use of this attribute to provide users with additional shortcuts to navigate directly to the collapsible element itself.
## Usage
The collapse plugin utilizes a few classes to handle the heavy lifting:
- `.collapse` hides the content
- `.collapse.in` shows the content
- `.collapsing` is added when the transition starts, and removed when it finishes
These classes can be found in `_animation.scss`.
### Via data attributes
Just add `data-toggle="collapse"` and a `data-target` to the element to automatically assign control of a collapsible element. The `data-target` attribute accepts a CSS selector to apply the collapse to. Be sure to add the class `collapse` to the collapsible element. If you'd like it to default open, add the additional class `in`.
To add accordion-like group management to a collapsible control, add the data attribute `data-parent="#selector"`. Refer to the demo to see this in action.
### Via JavaScript
Enable manually with:
{% highlight js %}
$('.collapse').collapse()
{% endhighlight %}
### Options
Options can be passed via data attributes or JavaScript. For data attributes, append the option name to `data-`, as in `data-parent=""`.