--- 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](https://markdotto.com/2012/02/27/bootstrap-explained-dropdowns/). Dropdowns are built on a third party library, [Popper](https://popper.js.org/), which provides dynamic positioning and viewport detection. Be sure to include [popper.min.js]({{< param "cdn.popper" >}}) before Bootstrap's JavaScript or use `bootstrap.bundle.min.js` / `bootstrap.bundle.js` which contains Popper. Popper isn't used to position dropdowns in navbars though as dynamic positioning isn't required. ## Accessibility The [WAI ARIA](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/WAI/PF/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 ` {{< /example >}} And with `` elements: {{< example >}}
{{< /example >}} The best part is you can do this with any button variant, too:
```html
``` ### Split button Similarly, create split button dropdowns with virtually the same markup as single button dropdowns, but with the addition of `.dropdown-toggle-split` for proper spacing around the dropdown caret. We use this extra class to reduce the horizontal `padding` on either side of the caret by 25% and remove the `margin-left` that's added for regular button dropdowns. Those extra changes keep the caret centered in the split button and provide a more appropriately sized hit area next to the main button.
```html
``` ## Sizing Button dropdowns work with buttons of all sizes, including default and split dropdown buttons.
```html
```
```html
``` ## Dark dropdowns Opt into darker dropdowns to match a dark navbar or custom style by adding `.dropdown-menu-dark` onto an existing `.dropdown-menu`. No changes are required to the dropdown items. {{< example >}}
{{< /example >}} And putting it to use in a navbar: {{< example >}} {{< /example >}} ## Directions {{< callout info >}} #### RTL Directions are mirrored when using Bootstrap in RTL, meaning `.dropstart` will appear on the right side. {{< /callout >}} ### Centered Make the dropdown menu centered below the toggle with `.dropdown-center` on the parent element. {{< example >}}
{{< /example >}} ### Dropup Trigger dropdown menus above elements by adding `.dropup` to the parent element.
```html
``` ### Dropup centered Make the dropup menu centered above the toggle with `.dropup-center` on the parent element. {{< example >}}
{{< /example >}} ### Dropend Trigger dropdown menus at the right of the elements by adding `.dropend` to the parent element.
```html
``` ### Dropstart Trigger dropdown menus at the left of the elements by adding `.dropstart` to the parent element.
```html
``` ## Menu items You can use `` or ` {{< /example >}} You can also create non-interactive dropdown items with `.dropdown-item-text`. Feel free to style further with custom CSS or text utilities. {{< example >}} {{< /example >}} ### Active Add `.active` to items in the dropdown to **style them as active**. To convey the active state to assistive technologies, use the `aria-current` attribute — using the `page` value for the current page, or `true` for the current item in a set. {{< example >}} {{< /example >}} ### Disabled Add `.disabled` to items in the dropdown to **style them as disabled**. {{< example >}} {{< /example >}} ## Menu alignment By default, a dropdown menu is automatically positioned 100% from the top and along the left side of its parent. You can change this with the directional `.drop*` classes, but you can also control them with additional modifier classes. Add `.dropdown-menu-end` to a `.dropdown-menu` to right align the dropdown menu. Directions are mirrored when using Bootstrap in RTL, meaning `.dropdown-menu-end` will appear on the left side. {{< callout info >}} **Heads up!** Dropdowns are positioned thanks to Popper except when they are contained in a navbar. {{< /callout >}} {{< example >}}
{{< /example >}} ### Responsive alignment If you want to use responsive alignment, disable dynamic positioning by adding the `data-bs-display="static"` attribute and use the responsive variation classes. To align **right** the dropdown menu with the given breakpoint or larger, add `.dropdown-menu{-sm|-md|-lg|-xl|-xxl}-end`. {{< example >}}
{{< /example >}} To align **left** the dropdown menu with the given breakpoint or larger, add `.dropdown-menu-end` and `.dropdown-menu{-sm|-md|-lg|-xl|-xxl}-start`. {{< example >}}
{{< /example >}} Note that you don't need to add a `data-bs-display="static"` attribute to dropdown buttons in navbars, since Popper isn't used in navbars. ### Alignment options Taking most of the options shown above, here's a small kitchen sink demo of various dropdown alignment options in one place. {{< example >}}
{{< /example >}} ## Menu content ### Headers Add a header to label sections of actions in any dropdown menu. {{< example >}} {{< /example >}} ### Dividers Separate groups of related menu items with a divider. {{< example >}} {{< /example >}} ### Text Place any freeform text within a dropdown menu with text and use [spacing utilities]({{< docsref "/utilities/spacing" >}}). Note that you'll likely need additional sizing styles to constrain the menu width. {{< example >}}

Some example text that's free-flowing within the dropdown menu.

And this is more example text.

{{< /example >}} ### Forms Put a form within a dropdown menu, or make it into a dropdown menu, and use [margin or padding utilities]({{< docsref "/utilities/spacing" >}}) to give it the negative space you require. {{< example >}}
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{{< /example >}} {{< example >}}
{{< /example >}} ## Dropdown options Use `data-bs-offset` or `data-bs-reference` to change the location of the dropdown. {{< example >}}
{{< /example >}} ### Auto close behavior By default, the dropdown menu is closed when clicking inside or outside the dropdown menu. You can use the `autoClose` option to change this behavior of the dropdown. {{< example >}}
{{< /example >}} ## CSS ### Variables {{< added-in "5.2.0" >}} As part of Bootstrap's evolving CSS variables approach, dropdowns now use local CSS variables on `.dropdown-menu` for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too. {{< scss-docs name="dropdown-css-vars" file="scss/_dropdown.scss" >}} Customization through CSS variables can be seen on the `.dropdown-menu-dark` class where we override specific values without adding duplicate CSS selectors. {{< scss-docs name="dropdown-dark-css-vars" file="scss/_dropdown.scss" >}} ### Sass variables Variables for all dropdowns: {{< scss-docs name="dropdown-variables" file="scss/_variables.scss" >}} Variables for the [dark dropdown](#dark-dropdowns): {{< scss-docs name="dropdown-dark-variables" file="scss/_variables.scss" >}} Variables for the CSS-based carets that indicate a dropdown's interactivity: {{< scss-docs name="caret-variables" file="scss/_variables.scss" >}} ### Mixins Mixins are used to generate the CSS-based carets and can be found in `scss/mixins/_caret.scss`. {{< scss-docs name="caret-mixins" file="scss/mixins/_caret.scss" >}} ## Usage Via data attributes or JavaScript, the dropdown plugin toggles hidden content (dropdown menus) by toggling the `.show` class on the parent `.dropdown-menu`. The `data-bs-toggle="dropdown"` attribute is relied on for closing dropdown menus at an application level, so it's a good idea to always use it. {{< callout info >}} On touch-enabled devices, opening a dropdown adds empty `mouseover` handlers to the immediate children of the `` element. This admittedly ugly hack is necessary to work around a [quirk in iOS' event delegation](https://www.quirksmode.org/blog/archives/2014/02/mouse_event_bub.html), which would otherwise prevent a tap anywhere outside of the dropdown from triggering the code that closes the dropdown. Once the dropdown is closed, these additional empty `mouseover` handlers are removed. {{< /callout >}} ### Via data attributes Add `data-bs-toggle="dropdown"` to a link or button to toggle a dropdown. ```html
``` ### Via JavaScript Call the dropdowns via JavaScript: ```js var dropdownElementList = Array.prototype.slice.call(document.querySelectorAll('.dropdown-toggle')) var dropdownList = dropdownElementList.map(function (dropdownToggleEl) { return new bootstrap.Dropdown(dropdownToggleEl) }) ``` {{< callout info >}} ##### `data-bs-toggle="dropdown"` still required Regardless of whether you call your dropdown via JavaScript or instead use the data-api, `data-bs-toggle="dropdown"` is always required to be present on the dropdown's trigger element. {{< /callout >}} ### Options {{< markdown >}} {{< partial "js-data-attributes.md" >}} {{< /markdown >}} {{< bs-table "table" >}} | Name | Type | Default | Description | | --- | --- | --- | --- | | `boundary` | string, element | `'scrollParent'` | Overflow constraint boundary of the dropdown menu (applies only to Popper's preventOverflow modifier). By default it's `clippingParents` and can accept an HTMLElement reference (via JavaScript only). For more information refer to Popper's [detectOverflow docs](https://popper.js.org/docs/v2/utils/detect-overflow/#boundary). | | `reference` | string, element | `'toggle'` | Reference element of the dropdown menu. Accepts the values of `'toggle'`, `'parent'`, an HTMLElement reference or an object providing `getBoundingClientRect`. For more information refer to Popper's [constructor docs](https://popper.js.org/docs/v2/constructors/#createpopper) and [virtual element docs](https://popper.js.org/docs/v2/virtual-elements/). | | `display` | string | `'dynamic'` | By default, we use Popper for dynamic positioning. Disable this with `static`. | | `offset` | number, string, function | `[0, 2]` | Offset of the dropdown relative to its target. You can pass a string in data attributes with comma separated values like: `data-bs-offset="10,20"`. When a function is used to determine the offset, it is called with an object containing the popper placement, the reference, and popper rects as its first argument. The triggering element DOM node is passed as the second argument. The function must return an array with two numbers: [skidding](https://popper.js.org/docs/v2/modifiers/offset/#skidding-1), [distance](https://popper.js.org/docs/v2/modifiers/offset/#distance-1). For more information refer to Popper's [offset docs](https://popper.js.org/docs/v2/modifiers/offset/#options). | | `autoClose` | boolean, string | `true` | Configure the auto close behavior of the dropdown: Note: the dropdown can always be closed with the ESC key | | `popperConfig` | null, object, function | `null` | To change Bootstrap's default Popper config, see [Popper's configuration](https://popper.js.org/docs/v2/constructors/#options). When a function is used to create the Popper configuration, it's called with an object that contains the Bootstrap's default Popper configuration. It helps you use and merge the default with your own configuration. The function must return a configuration object for Popper. | {{< /bs-table >}} #### Using function with `popperConfig` ```js var dropdown = new bootstrap.Dropdown(element, { popperConfig: function (defaultBsPopperConfig) { // var newPopperConfig = {...} // use defaultBsPopperConfig if needed... // return newPopperConfig } }) ``` ### Methods {{< bs-table >}} | Method | Description | | --- | --- | | `toggle` | Toggles the dropdown menu of a given navbar or tabbed navigation. | | `show` | Shows the dropdown menu of a given navbar or tabbed navigation. | | `hide` | Hides the dropdown menu of a given navbar or tabbed navigation. | | `update` | Updates the position of an element's dropdown. | | `dispose` | Destroys an element's dropdown. (Removes stored data on the DOM element) | | `getInstance` | Static method which allows you to get the dropdown instance associated to a DOM element, you can use it like this: `bootstrap.Dropdown.getInstance(element)` | | `getOrCreateInstance` | Static method which returns a dropdown instance associated to a DOM element or create a new one in case it wasn't initialized. You can use it like this: `bootstrap.Dropdown.getOrCreateInstance(element)`. | {{< /bs-table >}} ### Events All dropdown events are fired at the toggling element and then bubbled up. So you can also add event listeners on the `.dropdown-menu`'s parent element. `hide.bs.dropdown` and `hidden.bs.dropdown` events have a `clickEvent` property (only when the original Event type is `click`) that contains an Event Object for the click event. {{< bs-table >}} | Event type | Description | | --- | --- | | `show.bs.dropdown` | Fires immediately when the `show` instance method is called. | | `shown.bs.dropdown` | Fired when the dropdown has been made visible to the user and CSS transitions have completed. | | `hide.bs.dropdown` | Fires immediately when the `hide` instance method has been called. | | `hidden.bs.dropdown` | Fired when the dropdown has finished being hidden from the user and CSS transitions have completed. | {{< /bs-table >}} ```js var myDropdown = document.getElementById('myDropdown') myDropdown.addEventListener('show.bs.dropdown', function () { // do something... }) ```