web-vitals
Easily measure performance metrics in JavaScript
perfume.js
Web performance library for measuring all User-centric performance metrics, including the latest Web Vitals.
r2-lcp-js
Readium 2 LCP bits for NodeJS (TypeScript)
auto-lazyload
A lazy loading library for images, background, videos, Didn't require to change the HTML markup, just works and the performance is amazing!