@studio-freight/lenis NPM

Introduction

This is our take on smooth scroll, lightweight, hard-working, smooth as butter scroll. See Demo.

Installation

JavaScript

using a package manager:

npm i @studio-freight/lenis

import Lenis from '@studio-freight/lenis'

using scripts:

<script src="https://unpkg.com/@studio-freight/lenis@1.0.42/dist/lenis.min.js"></script>

Setup

Basic:

const lenis = new Lenis()

lenis.on('scroll', (e) => {
  console.log(e)
})

function raf(time) {
  lenis.raf(time)
  requestAnimationFrame(raf)
}

requestAnimationFrame(raf)

GSAP ScrollTrigger:

const lenis = new Lenis()

lenis.on('scroll', (e) => {
  console.log(e)
})

lenis.on('scroll', ScrollTrigger.update)

gsap.ticker.add((time)=>{
  lenis.raf(time * 1000)
})

gsap.ticker.lagSmoothing(0)

React:

See documentation for react-lenis.

Instance settings

Option	Type	Default	Description
`wrapper`	`HTMLElement, Window`	`window`	The element that will be used as the scroll container
`content`	`HTMLElement`	`document.documentElement`	The element that contains the content that will be scrolled, usually `wrapper`'s direct child
`eventsTarget`	`HTMLElement, Window`	`wrapper`	The element that will listen to `wheel` and `touch` events
`lerp`	`number`	`0.1`	Linear interpolation (lerp) intensity (between 0 and 1)
`duration`	`number`	`1.2`	The duration of scroll animation (in seconds). Useless if lerp defined
`easing`	`function`	`(t) => Math.min(1, 1.001 - Math.pow(2, -10 * t))`	The easing function to use for the scroll animation, our default is custom but you can pick one from Easings.net. Useless if lerp defined
`orientation`	`string`	`vertical`	The orientation of the scrolling. Can be `vertical` or `horizontal`
`gestureOrientation`	`string`	`vertical`	The orientation of the gestures. Can be `vertical`, `horizontal` or `both`
`smoothWheel`	`boolean`	`true`	Whether or not to enable smooth scrolling for mouse wheel events
`syncTouch`	`boolean`	`false`	Mimic touch device scroll while allowing scroll sync (can be unstable on iOS<16)
`syncTouchLerp`	`number`	`0.075`	Lerp applied during `syncTouch` inertia
`touchInertiaMultiplier`	`number`	`35`	Manage the the strength of `syncTouch` inertia
`wheelMultiplier`	`number`	`1`	The multiplier to use for mouse wheel events
`touchMultiplier`	`number`	`1`	The multiplier to use for touch events
`normalizeWheel`	`boolean`	`false`	Normalize wheel inputs across browsers (not reliable atm)
`infinite`	`boolean`	`false`	Enable infinite scrolling! (See example)
`autoResize`	`boolean`	`true`	Resize instance automatically based on `ResizeObserver`. If `false` you must resize manually using `.resize()`

Instance Props

Property	Type	Description
`animatedScroll`	`number`	Current scroll value
`dimensions`	`object`	Dimensions instance
`direction`	`number`	`1`: scrolling up, `-1`: scrolling down
`emitter`	`object`	Emitter instance
`options`	`object`	Instance options
`targetScroll`	`number`	Target scroll value
`time`	`number`	Time elapsed since instance creation
`actualScroll`	`number`	Current scroll value registered by the browser
`velocity`	`number`	Current scroll velocity
`isHorizontal` (getter)	`boolean`	Whether or not the instance is horizontal
`isScrolling` (getter)	`boolean`	Whether or not the scroll is being animated
`isSmooth` (getter)	`boolean`	Whether or not the scroll is animated
`isStopped` (getter)	`boolean`	Whether or not the user should be able to scroll
`limit` (getter)	`number`	Maximum scroll value
`progress` (getter)	`number`	Scroll progress from `0` to `1`
`rootElement` (getter)	`HTMLElement`	Element on which Lenis is instanced
`scroll` (getter)	`number`	Current scroll value (handles infinite scroll if activated)
`className` (getter)	`string`	`rootElement` className

Instance Methods

Method	Description	Arguments
`raf(time)`	Must be called every frame for internal usage.	`time`: in ms
`scrollTo(target, options)`	Scroll to target.	`target`: goal to reach`number`: value to scroll in pixels`string`: CSS selector or keyword (`top`, `left`, `start`, `bottom`, `right`, `end`)`HTMLElement`: DOM element`optionsoffset`(`number`): equivalent to `scroll-padding-toplerp`(`number`): animation lerp intensity`duration`(`number`): animation duration (in seconds)`easing`(`function`): animation easing`immediate`(`boolean`): ignore duration, easing and lerp`lock`(`boolean`): whether or not to prevent the user from scrolling until the target is reached`force`(`boolean`): reach target even if instance is stopped`onComplete`(`function`): called when the target is reached
`on(id, function)`	`id` can be any of the following instance events to listen.
`stop()`	Pauses the scroll
`start()`	Resumes the scroll
`resize()`	Compute internal sizes, it has to be used if `autoResize` option is `false`.
`destroy()`	Destroys the instance and removes all events.

Instance Events

Event	Callback Arguments
`scroll`	Lenis instance

Recommended CSS

html.lenis, html.lenis body {
  height: auto;
}

.lenis.lenis-smooth {
  scroll-behavior: auto !important;
}

.lenis.lenis-smooth [data-lenis-prevent] {
  overscroll-behavior: contain;
}

.lenis.lenis-stopped {
  overflow: hidden;
}

.lenis.lenis-scrolling iframe {
  pointer-events: none;
}

Considerations

Nested scroll

<div data-lenis-prevent>scroll content</div>

<div data-lenis-prevent-wheel>scroll content</div>

<div data-lenis-prevent-touch>scroll content</div>

See modal example

Anchor links

<a href="#anchor" onclick="lenis.scrollTo('#anchor')">scroll to anchor</a>

Limitations

no support for CSS scroll-snap
capped to 60fps on Safari (source) and 30fps on low power mode
smooth scroll will stop working over iframe since they don't forward wheel events
position fixed seems to lag on MacOS Safari pre-M1 (source)