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Locomotive Scroll

Detection of elements in viewport & smooth scrolling with parallax effects.

Installation

⚠️ Scroll-hijacking is a controversial practice that can cause usability, accessibility, and performance issues. Please use responsibly.

npm install locomotive-scroll

Usage

Basic

With simple detection.

HTML

<h1 data-scroll>Hey</h1>
<p data-scroll>👋</p>

CSS

Add the base styles to your CSS file.

locomotive-scroll.css

JS

With a bundler
import LocomotiveScroll from 'locomotive-scroll';

const scroll = new LocomotiveScroll();
Or without
<script src="locomotive-scroll.min.js"></script>
<script>
    (function () {
        var scroll = new LocomotiveScroll();
    })();
</script>

Get the JS file.

Smooth

With smooth scrolling and parallax.

<div data-scroll-container>
    <div data-scroll-section>
        <h1 data-scroll>Hey</h1>
        <p data-scroll>👋</p>
    </div>
    <div data-scroll-section>
        <h2 data-scroll data-scroll-speed="1">What's up?</h2>
        <p data-scroll data-scroll-speed="2">😬</p>
    </div>
</div>
import LocomotiveScroll from 'locomotive-scroll';

const scroll = new LocomotiveScroll({
    el: document.querySelector('[data-scroll-container]'),
    smooth: true
});

Note: scroll-sections are optional but recommended to improve performance, particularly in long pages.

Advanced

Make it do what you want.

With methods

<section id="js-target">Come here please.</section>
import LocomotiveScroll from 'locomotive-scroll';

const scroll = new LocomotiveScroll();
const target = document.querySelector('#js-target');

scroll.scrollTo(target);

With events

<!-- Using modularJS -->
<div data-scroll data-scroll-call="function, module">Trigger</div>
<!-- Using jQuery events -->
<div data-scroll data-scroll-call="EVENT_NAME">Trigger</div>
<!-- Or do it your own way 😎 -->
<div data-scroll data-scroll-call="{y,o,l,o}">Trigger</div>
import LocomotiveScroll from 'locomotive-scroll';

const scroll = new LocomotiveScroll();

scroll.on('call', func => {
    // Using modularJS
    this.call(...func);
    // Using jQuery events
    $(document).trigger(func);
    // Or do it your own way 😎
});

Instance options

Option Type Default Description
el object document Scroll container element.
name string 'scroll' Data attribute prefix (data-scroll-xxxx).
offset array(2) [0,0] Global in-view trigger offset : [bottom,top]
Use a string with % to use a percentage of the viewport height.
Use a numeric value for absolute pixels unit.
E.g. ["30%",0], [100,0], ["30%", 100]
repeat boolean false Repeat in-view detection.
smooth boolean false Smooth scrolling.
initPosition object { x: 0, y: 0 } Smooth only
An object defining the initial scroll coordinates on a smooth instance. For example: { x: 0, y: 1000 }
direction string vertical Smooth only
Scroll direction: vertical or horizontal
lerp number 0.1 Smooth only
Linear interpolation (lerp) intensity. Float between 0 and 1.
This defines the "smoothness" intensity. The closer to 0, the smoother.
getDirection boolean false Add direction to scroll event.
getSpeed boolean false Add speed to scroll event.
class string is-inview Element in-view class.
initClass string has-scroll-init Initialize class.
scrollingClass string has-scroll-scrolling Is scrolling class.
draggingClass string has-scroll-dragging Is dragging class.
smoothClass string has-scroll-smooth Has smooth scrolling class.
scrollbarContainer object false Smooth only
Specifies the container element for the scrollbar to be appended in. If false, scrollbar will be appended to the body.
scrollbarClass string c-scrollbar Smooth only
Scrollbar element class.
multiplier number 1 Smooth only
Factor applied to the scroll delta, allowing to boost/reduce scrolling speed (regardless of the platform).
firefoxMultiplier number 50 Smooth only
Boost scrolling speed of Firefox on Windows.
touchMultiplier number 2 Smooth only
Multiply touch action to scroll faster than finger movement.
scrollFromAnywhere boolean false Smooth only
By default locomotive-scroll listens for scroll events only on the scroll container (el option). With this option set to true, it listens on the whole document instead.
gestureDirection string vertical Smooth only
Defines which gesture direction(s) scrolls in your instance. You can use :
  • vertical
  • horizontal
  • both
tablet & smartphone object Object allowing to override some options for a particular context. You can specify:
  • smooth
  • direction
  • horizontalGesture
For tablet context you can also define breakpoint (integer, defaults to 1024) to set the max-width breakpoint for tablets.
reloadOnContextChange boolean false Allows to reload the page when switching between desktop, tablet and smartphone contexts. It can be useful if your page changes a lot between contexts and you want to reset everything.
resetNativeScroll boolean true Sets history.scrollRestoration = 'manual' and calls window.scrollTo(0, 0) on locomotive-scroll init in Native Class. Useful if you use transitions with native scrolling, otherwise we advise to set it to false if you don't want to break History API's scroll restoration feature.

Element attributes

Attribute Values Description
data-scroll Detect if in-view.
data-scroll-id string (Optional) Useful if you want to scope your element and get the progress of your element in the viewport for example.
data-scroll-container Defines the scroll container. Required for basic styling.
data-scroll-section Defines a scrollable section. Splitting your page into sections may improve performance.
data-scroll-class string Element in-view class.
data-scroll-offset string Element in-view trigger offset : bottom,top
First value is bottom offset, second (optional) is top offset.
Percent is relative to viewport height, otherwise it's absolute pixels.
E.g. "10", "100,50%", "25%, 15%"
data-scroll-repeat boolean Element in-view detection repeat.
data-scroll-call string Element in-view trigger call event.
data-scroll-position string top, bottom, left or right
Window position of in-view trigger.
data-scroll-speed number Smooth only
Element parallax speed. A negative value will reverse the direction.
data-scroll-delay number Smooth only
Element's parallax lerp delay.
data-scroll-direction string Smooth only
Element's parallax direction. vertical or horizontal
data-scroll-sticky Smooth only
Sticky element. Starts and stops at data-scroll-target position.
data-scroll-target string Smooth only
Target element's in-view position.

Instance methods

Method Description Arguments
init() Reinitializes the scroll.
on(eventName, function) Listen instance events ⬇.
update() Updates all element positions.
destroy() Destroys the scroll events.
start() Restarts the scroll events.
stop() Stops the scroll events.
scrollTo(target, options) Scroll to a target.
target: Defines where you want to scroll. Available values types are :
  • node : a dom element
  • string : you can type your own selector, or use values "top" and "bottom" to reach scroll boundaries
  • int : An absolute scroll coordinate in pixels
options (optional, object) : Settings object. Available values are:
  • offset (integer) : Defines an offset from your target. E.g. -100 if you want to scroll 100 pixels above your target
  • callback (function) : Called when scrollTo completes (note that it won't wait for lerp to stabilize)
  • duration (integer) : Defines the duration of the scroll animation in milliseconds. Defaults to 1000
    Smooth only
  • easing (array) : An array of 4 floats between 0 and 1 defining the bezier curve for the animation's easing.
    Defaults to [0.25, 0.00, 0.35, 1.00]
    See https://greweb.me/2012/02/bezier-curve-based-easing-functions-from-concept-to-implementation
    Keep in mind this will also be affected by the lerp unless you set disableLerp to true.
    Smooth only
  • disableLerp (boolean) : Lerp effect won't be applied if set to true
    Smooth only

Instance events

Event Arguments Description
scroll obj Returns scroll instance (position, limit, speed, direction and current in-view elements).
call func Trigger if in-view. Returns your string or array if contains ,.

Progressive playing animations example (like gsap)

All data-scroll elements have a progress value. In the on scroll event you can get all current in-view elements.

HTML

<h1 data-scroll data-scroll-id="hey">Hey</h1>

JS

scroll.on('scroll', (args) => {
    // Get all current elements : args.currentElements
    if(typeof args.currentElements['hey'] === 'object') {
        let progress = args.currentElements['hey'].progress;
        console.log(progress);
        // ouput log example: 0.34
        // gsap example : myGsapAnimation.progress(progress);
    }
});

Dependencies

Name Description
Virtual Scroll Custom scroll event with inertia/momentum.
modularScroll Elements in viewport detection. Forked from it, not a dependency.
bezier-easing Allows to define an easing to scrollTo movement

Browser support

Works on most modern browsers. Chrome, Firefox, Safari, Edge...

To get IE 11 support, you need polyfills. You can use your own or include these before our script.

<script nomodule src="https://cdnjs.cloudflare.com/ajax/libs/babel-polyfill/7.6.0/polyfill.min.js" crossorigin="anonymous"></script>
<script nomodule src="https://polyfill.io/v3/polyfill.min.js?features=Object.assign%2CElement.prototype.append%2CNodeList.prototype.forEach%2CCustomEvent%2Csmoothscroll" crossorigin="anonymous"></script>

Who's using Locomotive Scroll?

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