Scrollspy

Bootstrap 5 Scrollspy component

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

Section 1

Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore earum natus vel minima quod error maxime, molestias ut. Fuga dignissimos nisi nemo necessitatibus quisquam obcaecati et reiciendis quaerat accusamus numquam.

Section 2

Section 3 Subsection A

Subsection B


          <div class="row">
            <div class="col-md-8">
              <!-- Spied element -->
              <div
                data-mdb-spy="scroll"
                data-mdb-target="#scrollspy1"
                data-mdb-offset="0"
                class="scrollspy-example"
              >
                <section id="example-1">
                  <h3>Section 1</h3>
                  ...
                </section>
                <section id="example-2">
                  <h3>Section 2</h3>
                  ...
                </section>
                <section id="example-3">
                  <h3>Section 3</h3>
                  ...
                  <section id="example-sub-A">
                    <h3>Subsection A</h3>
                    ...
                  </section>
                  <section id="example-sub-B">
                    <h3>Subsection B</h3>
                    ...
                  </section>
                </section>
                <section id="example-4">
                  <h3>Section 4</h3>
                  ...
                </section>
              </div>
              <!-- Spied element -->
            </div>

            <div class="col-md-4">
              <!-- Scrollspy -->
              <div id="scrollspy1" class="sticky-top">
                <ul class="nav flex-column nav-pills menu-sidebar">
                  <li class="nav-item">
                    <a class="nav-link" href="#example-1">Section 1</a>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link" href="#example-2">Section 2</a>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link" href="#example-3">Section 3</a>
                    <ul class="nav flex-column ps-3">
                      <li class="nav-item">
                        <a class="nav-link" href="#example-sub-A">Subsection A</a>
                      </li>
                      <li class="nav-item">
                        <a class="nav-link" href="#example-sub-B">Subsection B</a>
                      </li>
                    </ul>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link" href="#example-4">Section 4</a>
                  </li>
                </ul>
              </div>
              <!-- Scrollspy -->
            </div>
          </div>


          /* Styles required only for the example above */
          .scrollspy-example {
            position: relative;
            height: 200px;
            overflow: auto;
          }

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.

Section 1

Section 2

Section 3 Subsection A

Subsection B

Section 4

HTML
CSS


          <div class="row">
            <div class="col-md-8">
              <!-- Spied element -->
              <div
                data-mdb-spy="scroll"
                data-mdb-target="#scrollspy-collapsible"
                data-mdb-offset="0"
                class="scrollspy-example"
              >
                <section id="example-1-collapsible">
                  <h3>Section 1</h3>
                  ...
                </section>
                <section id="example-2-collapsible">
                  <h3>Section 2</h3>
                  ...
                </section>
                <section id="example-3-collapsible">
                  <h3>Section 3</h3>
                  ...
                  <section id="example-sub-A-collapsible">
                    <h3>Subsection A</h3>
                    ...
                  </section>
                  <section id="example-sub-B-collapsible">
                    <h3>Subsection B</h3>
                    ...
                  </section>
                </section>
                <section id="example-4-collapsible">
                  <h3>Section 4</h3>
                  ...
                </section>
              </div>
              <!-- Spied element -->
            </div>

            <div class="col-md-4">
              <!-- Scrollspy -->
              <div id="scrollspy-collapsible" class="sticky-top">
                <ul class="nav flex-column nav-pills menu-sidebar">
                  <li class="nav-item">
                    <a class="nav-link" href="#example-1-collapsible">Section 1</a>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link" href="#example-2-collapsible">Section 2</a>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link collapsible-scrollspy" href="#example-3-collapsible">Section 3</a>
                    <ul class="nav flex-column ps-3">
                      <li class="nav-item">
                        <a class="nav-link" href="#example-sub-A-collapsible">Subsection A</a>
                      </li>
                      <li class="nav-item">
                        <a class="nav-link" href="#example-sub-B-collapsible">Subsection B</a>
                      </li>
                    </ul>
                  </li>
                  <li class="nav-item">
                    <a class="nav-link" href="#example-4-collapsible">Section 4</a>
                  </li>
                </ul>
              </div>
              <!-- Scrollspy -->
            </div>
          </div>


          /* Styles required only for the example above */
          .scrollspy-example-collapsible {
            position: relative;
            height: 200px;
            overflow: auto;
          }

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.

Scrollspy - API

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.

HTML
CSS


          <body data-mdb-spy="scroll" data-mdb-target="#navbar-example">
            ...
            <div id="navbar-example">
              <ul class="nav nav-tabs" role="tablist">
                ...
              </ul>
            </div>
            ...
          </body>

 body { position: relative; }

Via JavaScript

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

JavaScript


          const scrollSpy = new mdb.ScrollSpy(document.body, {
            target: '#navbar-example'
          })

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.

jQuery


          $('.example-class').scrollSpy(options);

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)

JavaScript


        const dataSpyList = [].slice.call(document.querySelectorAll('[data-mdb-spy="scroll"]'))
        dataSpyList.forEach((dataSpyEl) => {
          mdb.ScrollSpy.getInstance(dataSpyEl).refresh()
        })

Events

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

JavaScript


      const firstScrollSpyEl = document.querySelector('[data-mdb-spy="scroll"]')
      firstScrollSpyEl.addEventListener('activate.mdb.scrollspy', () => {
        // do something...
      })

Import

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

JavaScript


        import { ScrollSpy } from 'mdb-ui-kit';