react-scroll-parallax

React Scroll Parallax

React components to create parallax scroll effects for banners, images or any other DOM elements. Uses a single scroll listener via Parallax Controller to add vertical or horizontal scrolling based offsets to elements based on their position in the viewport. Optimized to reduce jank on scroll and works with universal (server-side rendered) React apps.

If you're coming from V2, here's a migration guide.

Examples

V3 Storybook

See the Storybook for example usage of each component

• Storybook - Source

Demos

Some demo websites using Parallax components

• Demo 1 - Source
• Demo 2 - Source

Install

With npm

npm i react-scroll-parallax --save

or yarn

yarn add react-scroll-parallax

Documentation

• Example Usage
• <Parallax>
  • Parallax Props
• <ParallaxBanner>
  • Banner Usage
  • Banner Props
  • Banner Layers Prop
• <ParallaxProvider>
  • ParallaxProvider Props
• Parallax Controller Context
  • Available Methods
• Browser Support
• Optimizations to Reduce Jank
  • PSA

Usage

The <ParallaxProvider> must wrap the component tree that contains all <Parallax> components. This should be a top level component like <App>. For example:

import { ParallaxProvider } from 'react-scroll-parallax';

function App() {
  render() {
    return (
      <ParallaxProvider>
        <AppRoutes />
      </ParallaxProvider>
    );
  }
}

Then import the Parallax component and use it anywhere within the provider. Here's an example that will transform the element on the translateY axis starting at -20% and ending at 20% (translateY = [-20, 20] *percent is assumed with no provided unit).

import { Parallax } from 'react-scroll-parallax';

const VerticalParallax = () => (
  <Parallax translateY={[-20, 20]}>
    <div className="my-thing" />
  </Parallax>
);

Example with transforms on the translateX axis starting at -100px and ending at 200px (translateX = ['-100px', '200px']).

import { Parallax } from 'react-scroll-parallax';

const HorizontalParallax = () => (
  <Parallax translateX={['-100px', '200px']}>
    <div className="my-thing" />
  </Parallax>
);

How it works

TODO: Explain how and when effects are applied with some illustrations and demos.

1. This lib was first designed to be used on elements that scroll naturally with the page. If you use fixed positioning you will likely want to set the startScroll and endScroll values manually, or use a targetElement to indicate scroll progress.
2. Scroll state and positions of elements on the page are cached for performance reasons. This means that if the page height changes (most likely from images loading) after components mount the controller won't properly determine when the elements are in view. To correct this you can call the parallaxController.update() method from any child component of the <ParallaxProvider /> via context. More details on how here: Parallax Controller Context.

Troubleshooting

If you're encountering issues like the parallax element jumping around or becoming stuck, there's a few likely culprits. Since this lib caches important positioning states it's possible for these to be outdated and incorrect. The most likely cause for this type of problem is the result of images loading and increasing the height of an element and/or the page. This can be fixed easily by updating the cache.

Optimizations to Reduce Jank

Considerations have been taken to reduce jank -- please read more here on how this is done

PSA

Even with optimizations scroll effects can cause jank. It's also important to keep in mind that scroll effects are usually not critical to a users experience and sometimes can be annoying.

If you use these components make sure you seriously consider the following:

• Keep images small (do not use inappropriately high resolutions) and optimized (use appropriate compression)
• Reduce the number of scroll effects on elements in view and on the page in total
• Disable the use — or limit the amount — of scroll effects for users on mobile devices

Follow the above and you should keep scrolling smooth and users happy.