Awesome Open Source
Awesome Open Source

A JavaScript vanilla library to scroll based reveal animations

murphy.js is a lightweight JavaScript animation library with a simple implementation way.
All this works by joining of data-attributes, Web animate API and Intersection Observer API.

Demo | Why use murphy | Getting started | Examples | Documentation | Browser support

Why use murphy

  • ⚡️ Lightweight library (only 1.7KB gzipped).

  • 🍎 Easy and fast implementation.

  • 🎮 Total control of IntersectionObserver parameters.

  • 🎨 Full customization of time, duration, ease, delay and distance of each element individually.

  • 🎁 Some animations implemented by default.

  • 🏝 Plug and play solution to landing pages and simple projects.

  • ❎ Native fallback to not supported browsers.

Getting started


Via npm:

$ npm install murphyjs

Via file include:

Download file here and link in your HTML.

<script src="./murphy/index.js"></script>


Just do three steps:

⛳   Tag your HTML

In your markup, decore your element with attribute data-murphy.

<div data-murphy="left-to-right">Any content here</div>

The default effect of murphy is bottom-to-top, but it's possible use top-to-bottom, left-to-right and right-to-left too.

🔌   Reset your CSS

In your CSS, reset all the tagged elements.

*[data-murphy] {
  opacity: 0;

🚀   Start murphy

In Javascript side, just import and run play when your page is completely loaded to start monitoring decorated elements.

import murphy from "murphyjs";
And trigger

Or call from window

If you added murphy via file include, just access murphy's functions in window:
// or just

That is enough to work! 🤟🏿


1. This data-attributes:

<p data-murphy="bottom-to-top">Bottom to top</p>
<p data-murphy="top-to-bottom">Top to bottom</p>
<p data-murphy="left-to-right">Left to right</p>
<p data-murphy="right-to-left">Right to left</p>

Will result in that:

2. To do the same effect that murphy's logo, use:

<p data-murphy="bottom-to-top">m</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="400">u</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="500">r</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="600">p</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="700">h</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="800">y</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="900">.</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="1000">j</p>
<p data-murphy="bottom-to-top" data-murphy-animation-delay="1100">s</p>


🚨 Important

These animations are triggered when scrolling the page, but when the tagged elements are already within the bounds of the screen, everything works like appearance animations that React Transition Group already does. So if you need animations on the first load of site, murphy is for you!



You can configure the animation of each decorated element individually. Beyond the data-murphy attribute, other attributes are available:

Attribute Value type Default value What controls
data-murphy String 'bottom-to-top' -
data-murphy-appearance-distance Int 50 (px) -
data-murphy-element-distance Int 30 (px) -
data-murphy-ease String 'ease' (can be a cubic-bezier) -
data-murphy-animation-delay Int 300 (ms) -
data-murphy-element-threshold Int 1 -
data-murphy-animation-duration Int 300 (ms) -


Method What happens
play Start monitoring on element in DOM tagged with data-murphy
reset Resets all data-murphy elements to their initial state.

Browser support

Chrome Safari IE / Edge Firefox Opera
58+ 12.1+ Not (yet) supported 55+ 62+


The code is available under the MIT License.

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