---
layout: docs
title: Dropdowns
description: Toggle contextual overlays for displaying lists of links and more with the Bootstrap dropdown plugin.
group: components
toc: true
---
## Overview
Dropdowns are toggleable, contextual overlays for displaying lists of links and more. They're made interactive with the included Bootstrap dropdown JavaScript plugin. They're toggled by clicking, not by hovering; this is [an intentional design decision.](http://markdotto.com/2012/02/27/bootstrap-explained-dropdowns/)
Dropdowns are built on a third party library, [Popper.js](https://popper.js.org), which provides dynamic positioning and viewport detection. Be sure to include [popper.min.js](https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.10.1/umd/popper.min.js) before Bootstrap's JavaScript.
## Accessibility
The [WAI ARIA](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/TR/wai-aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. ARIA menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus.
Bootstrap's dropdowns, on the other hand, are designed to be generic and applicable to a variety of situations and markup structures. For instance, it is possible to create dropdowns that contain additional inputs and form controls, such as search fields or login forms. For this reason, Bootstrap does not expect (nor automatically add) any of the `role` and `aria-` attributes required for true ARIA menus. Authors will have to include these more specific attributes themselves.
However, Bootstrap does add built-in support for most standard keyboard menu interactions, such as the ability to move through individual `.dropdown-item` elements using the cursor keys and close the menu with the ESC key.
## Examples
Wrap the dropdown's toggle (your button or link) and the dropdown menu within `.dropdown`, or another element that declares `position: relative;`. Dropdowns can be triggered from `` or `