ZapLoad

ZapLoad is a very lightweight (~2.9KB) JavaScript library for delaying the loading (also known as lazyload) of various src elements such as img, video, script, object, and iframe.

Key Features

• Lightweight, only sized about 2.9KB and 1.7KB for the minified version.
• Supports img, video, script, object, and iframe.
• Place it anywhere inside your html.
• Build on top of vanilla JS - no additional library/frameworks.
• Good for SEO and page load speed optimizations.

Configuration

There are 5 delay types configurations:

• scroll: Delays loading until the user scrolls
• scroll [selector]: Delays loading until the user scrolls to the selector element in the viewport
• click [selector]: Delays loading until the user clicks on the selector element
• timeout [time in ms]: Delays loading for a specific time (in milliseconds)
• custom: Delays loading until it is called in JavaScript

Examples

HTML

Add .zapload to elements and data-zapload attribute with some values. Then, change the src attr to data-src. You can set the default src too (e.g. low-res img before the real img loaded).

<!-- Load when user scroll min. of 1px -->
<img class="zapload" data-zapload="scroll" data-src="https://via.placeholder.com/300x200">

<!-- Load when user scrolls to #home -->
<img class="zapload" data-zapload="scroll #home" data-src="https://via.placeholder.com/300x200">

<!-- Load when user click #home -->
<img class="zapload" data-zapload="click #home" data-src="https://via.placeholder.com/300x200">

<!-- Load after 3s (3000ms) -->
<img class="zapload" data-zapload="timeout 3000" data-src="https://via.placeholder.com/300x200">

JavaScript for custom

function doSomething(){
  zapload("#logo"); // Load after doSomething() called
}

License

MIT