Trig.js powers dynamic, CSS-driven animate-on-scroll effects using CSS variables and element position data, making AOS effortless. Create custom animations in CSS or use trig-animations.css for ready-made effects—full control or quick setup. Perfect for storytelling websites.

See it in action here: https://idev-games.github.io/Trig-JS/

Find more examples here: https://github.com/iDev-Games/Trig-JS-Examples

Find our codepen examples here: https://codepen.io/collection/wkBWzm

Keep up to date with tutorials, examples and informtion on my dev.to: https://dev.to/idevgames

Trig-Animations.css documentation can be found here: https://idev-games.github.io/Trig-JS/animations.html

You can download from Github.

Install with NPM

npm i trig-js

Use Trig.js from a CDN

https://cdn.jsdelivr.net/npm/trig-js/src/trig.min.js

Trig.js is a super simple, efficient and lightweight way of making CSS scroll animations that react to the position of your HTML elements. You can also use Trig.js to trigger CSS animations once an element appears on screen.

Using nothing but the power of CSS, HTML and Trig.js. You can make the same effects as you see here: https://idev-games.github.io/Trig-JS/! Not just that, Trig.js is really lightweight with a filesize of ! Trig.js is created with javascript and doesn't require any dependencies.

Trig.js is really simple and quick to work with. You can use Trig.js even if you arn't familiar with javascript.

Trig.js is the perfect solution for CSS scroll animations in any project by developers of any skill level for both light or heavy usage. Making it the perfect alternative to libraries like scrollmagic or GSAP scrolltrigger for most of your website animation needs.

Configurable predefined scroll animations for your projects https://idev-games.github.io/Trig-JS/animations.html

All you need to do is add the dist trig.js file into your projects JS folder and add the following code with your trig.js location as the src. Put this code in to your head HTML tags

<script src="/js/trig.min.js"></script>

Or just add a CDN instead

<script src="https://cdn.jsdelivr.net/npm/trig-js/src/trig.min.js"></script>

To activate trig.js add the data attribute "data-trig" or a class "enable-trig" to your html element. To trigger animations trig.js will place classes of "trig", as well as "trig-up" or "trig-down", onto your element when it appears on screen and depending from which direction.

<div class="fadeIn" data-trig> </div>

.fadeIn{ 
    opacity:0;
}
.fadeIn.trig{ 
    animation: fadeIn 1s normal forwards ease-in-out; 
}
@keyframes fadeIn { 
  0% { 
    opacity:0;
  } 
  100% { 
    opacity:1; 
  } 
}

Trig.js calculates the percentage that the element is on screen and creates CSS variables that you can use with CSS transform etc.

<div class="element" data-trig data-trig-var="true"> </div>

.element{ 
    transform: translateX( var(--trig) );
}

The CSS variables you can use by adding data-trig-var="true", data-trig-pixels="true" or data-trig-degrees="true" are:

var(--trig) /* Percentage */
var(--trig-reverse) /* Reverse percentage */
var(--trig-px) /* Pixels */
var(--trig-px-reverse) /* Reverse pixels */
var(--trig-deg) /* Degrees */
var(--trig-deg-reverse) /* Reverse degrees */

The data attribute will also update in increments of 10 so you can use CSS attribute selectors like:

[data-trig-var="50"],
[data-trig-var="60"],
[data-trig-var="70"],
[data-trig-var="80"],
[data-trig-var="90"],
[data-trig-var="100"]{
  transform: translateX( var(--trig) );
} 

for more control.

Trig.js creates a class of "trig-scroll-up" or "trig-scroll-down" onto the body of the document depending on the last scroll direction.

Trig.js creates a class of "trig-scroll-top" or "trig-scroll-bottom" onto the body of the document depending on the last scroll position. To give the ability to make something happen at different break points down the page. The classes "trig-scroll-25", "trig-scroll-50" and "trig-scroll-75" are added to the body of the document depending on the scroll position percentage down the page.

You can use the below data attributes for additional features

<div id="yourelement" data-trig-min="-100" data-trig-max="100" data-trig-offset="0" data-trig-negativeOffset="0" data-trig-height="0" data-trig-global="false" data-trig> </div>

Check out the code of the documentation as an example.

https://github.com/iDev-Games/Trig-JS/blob/main/index.html

Cursor.js is the perfect companion to Trig.js for complete control over both scroll and cursor interactions using the same elegant CSS-first philosophy!

Together they provide:

• Trig.js: Scroll position data (vertical)
• Cursor.js: Mouse position data (horizontal + vertical)
• Same API patterns and conventions
• Same performance optimizations
• Zero dependencies for both
• Minimal footprint

Perfect pair for modern, interactive web experiences!