Automatically update Bootstrap navigation or list group components based on scroll position to indicate which link is currently active in the viewport.

Note: Read the API tab to find all available options and advanced customization

Basic example

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Collapsible

Hides all subsections of unactive section. To use it, simply add .collapsible-scrollspy class to the <a> element of section you want to set to be collapsible.

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How it works

Scrollspy has a few requirements to function properly:

It must be used on a Bootstrap nav component or list group.
Scrollspy requires position: relative; on the element you’re spying on, usually the <body>.
When spying on elements other than the <body>, be sure to have a height set and overflow-y: scroll; applied.
Anchors (<a>) are required and must point to an element with that id.

When successfully implemented, your nav or list group will update accordingly, moving the .active class from one item to the next based on their associated targets.

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Usage

Via data attributes

To easily add scrollspy behavior to your topbar navigation, add data-mdb-spy="scroll" to the element you want to spy on (most typically this would be the <body>). Then add the data-mdb-target attribute with the ID or class of the parent element of any MDB .nav component.

{{< mdbsnippet/wrapper "HTML,CSS" >}} {{< mdbsnippet/code active=true lang="html" >}} ... ... {{< /mdbsnippet/code >}} {{< mdbsnippet/code lang="css">}} body { position: relative; } {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

Via JavaScript

After adding position: relative; in your CSS, call the scrollspy via JavaScript:

{{< mdbsnippet/wrapper "JS" >}} {{< mdbsnippet/code active=true lang="js" >}} const scrollSpy = new mdb.ScrollSpy(document.body, { target: '#navbar-example' }) {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

Resolvable ID targets required: Navbar links must have resolvable id targets. For example, a <a href="#home">home</a> must correspond to something in the DOM like <div id="home"></div>.

Non-visible target elements ignored: Target elements that are not visible will be ignored and their corresponding nav items will never be highlighted.

Via jQuery

Note: By default, MDB does not include jQuery and you have to add it to the project on your own.

{{< mdbsnippet/wrapper "jQuery" >}} {{< mdbsnippet/code active=true lang="js">}} $(document).ready(() => { $('.example-class').scrollSpy(options); }); {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

Options

Options can be passed via data attributes or JavaScript. For data attributes, append the option name to data-mdb-, as in data-mdb-offset="".

Name	Type	Default	Description
`offset`	number	`10`	Pixels to offset from top when calculating position of scroll.
`method,`	string	`auto,`	Finds which section the spied element is in. `auto,` will choose the best method to get scroll coordinates. `offset,` will use the `Element.getBoundingClientRect(),` method to get scroll coordinates. `position,` will use the `HTMLElement.offsetTop,` and `HTMLElement.offsetLeft,` properties to get scroll coordinates.
`target,`	string \| jQuery object \| DOM element		Specifies element to apply Scrollspy plugin.

Methods

Name	Description	Example
`refresh`	When using scrollspy in conjunction with adding or removing of elements from the DOM, you’ll need to call the refresh method	instance.refresh()
`dispose`	Destroys an element’s tab.	instance.dispose()
`getInstance`	Static method which allows you to get the scrollspy instance associated to a DOM element.	ScrollSpy.getInstance(dataSpyEl)

{{< mdbsnippet/wrapper "JS" >}} {{< mdbsnippet/code active=true lang="js" >}} const dataSpyList = [].slice.call(document.querySelectorAll('[data-mdb-spy="scroll"]')) dataSpyList.forEach((dataSpyEl) => { mdb.ScrollSpy.getInstance(dataSpyEl).refresh() }) {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

Events

Event type	Description
`activate.mdb.scrollspy`	This event fires on the scroll element whenever a new item becomes activated by the scrollspy.

{{< mdbsnippet/wrapper "JS" >}} {{< mdbsnippet/code active=true lang="js" >}} const firstScrollSpyEl = document.querySelector('[data-mdb-spy="scroll"]') firstScrollSpyEl.addEventListener('activate.mdb.scrollspy', () => { // do something... }) {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

Import

MDB UI KIT also works with module bundlers. Use the following code to import this component:

{{< mdbsnippet/wrapper "JS" >}} {{< mdbsnippet/code active=true lang="js" >}} import { ScrollSpy } from 'mdb-ui-kit'; {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

CSS variables

As part of MDB’s evolving CSS variables approach, scrollspy now use local CSS variables for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.

Scrollspy CSS variables are in different classes which belong to this component. To make it easier to use them, you can find below all of the used CSS variables.

{{< mdbsnippet/wrapper "CSS" >}} {{< mdbsnippet/code active=true lang="css" >}} // .nav-pills // &.menu-sidebar --#{$prefix}scrollspy-menu-sidebar-font-size: #{$scrollspy-menu-sidebar-font-size}; --#{$prefix}scrollspy-menu-sidebar-color: #{$scrollspy-menu-sidebar-color}; --#{$prefix}scrollspy-menu-sidebar-line-height: #{$scrollspy-menu-sidebar-line-height}; --#{$prefix}scrollspy-menu-sidebar-padding-x: #{$scrollspy-menu-sidebar-padding-x}; --#{$prefix}scrollspy-menu-sidebar-font-weight: #{$scrollspy-menu-sidebar-font-weight}; --#{$prefix}scrollspy-menu-sidebar-transition: #{$scrollspy-menu-sidebar-transition}; --#{$prefix}scrollspy-menu-sidebar-margin-y: #{$scrollspy-menu-sidebar-margin-y}; // .nav-link.active, // .show > .nav-link --#{$prefix}scrollspy-menu-sidebar-active-color: #{$scrollspy-menu-sidebar-active-color}; --#{$prefix}scrollspy-menu-sidebar-active-font-weight: #{$scrollspy-menu-sidebar-active-font-weight}; --#{$prefix}scrollspy-menu-sidebar-active-border-width: #{$scrollspy-menu-sidebar-active-border-width}; --#{$prefix}scrollspy-menu-sidebar-active-border-color: #{$scrollspy-menu-sidebar-active-border-color}; // .collapsible-scrollspy ~ .nav --#{$prefix}scrollspy-collapsible-nav-transition-time: #{$scrollspy-collapsible-nav-transition-time}; {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

SCSS variables

{{< mdbsnippet/wrapper "SCSS" >}} {{< mdbsnippet/code active=true lang="scss" >}} $scrollspy-menu-sidebar-font-size: 0.8rem; $scrollspy-menu-sidebar-color: #262626; $scrollspy-menu-sidebar-line-height: 1.1rem; $scrollspy-menu-sidebar-padding-x: 5px; $scrollspy-menu-sidebar-font-weight: 400; $scrollspy-menu-sidebar-transition: all 0.2s ease-in-out; $scrollspy-menu-sidebar-margin-y: 3px; $scrollspy-menu-sidebar-active-color: $primary; $scrollspy-menu-sidebar-active-font-weight: 600; $scrollspy-menu-sidebar-active-border-width: 0.125rem; $scrollspy-menu-sidebar-active-border-color: $primary; $scrollspy-collapsible-nav-transition-time: 0.5s; {{< /mdbsnippet/code >}} {{< /mdbsnippet/wrapper >}}

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Basic example

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Collapsible

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How it works

Related resources

{{< docs-title >}} - API

Usage

Via data attributes

Via JavaScript

Via jQuery

Options

Methods

Events

Import

CSS variables

SCSS variables