aFarkas/lazysizes

LazyLoad is a lightweight, flexible script that speeds up your website by deferring the loading of your below-the-fold images, backgrounds, videos, iframes and scripts to when they will enter the viewport. Written in plain "vanilla" JavaScript, it leverages IntersectionObserver, supports responsive images and enables native lazy loading.

Relocate resource intensive third-party scripts off of the main thread and into a web worker. 🎉

⚡️Faster subsequent page-loads by prefetching in-viewport links during idle time

📦 Workbox: JavaScript libraries for Progressive Web Apps

Animate on scroll library

🌊 A flexible and fun JavaScript file upload library

A customizable, modular, responsive, lightbox gallery plugin.

The javascript library for magical scroll interactions.

Essential metrics for a healthy site.