To lazyload images, backgrounds and videos, we use lazysizes. Be sure to read the documentation.

How to use

Lazysizes also supports responsive images, but again, just read the documentation. If you need support for background-images, videos and what not see unveilhooks.

A lazy-loaded image

A lazy-loaded responsive image

Resize your browser (a refresh is needed in some browsers). If you'd like to make it crossbrowser, consider including Picturefill 3 (in alpha as of this writing) or Respimage.