vanilla-lazyload

A fast, lightweight script to load images as they enter the viewport. SEO friendly, it supports responsive images (both srcset + sizes and picture) and progressive JPEG

lazyloadvanillaresponsiveimagespicturesrcsetSEOintersectionObserversizesprogressiveperformanceperfmattersasyncno-jquery

https://www.andreaverlicchi.eu/vanilla-lazyload/