JavaScript Lazy Load

simple_image_lazy_load.js

"use strict";
var fLazy = (function(doc){
  return { "init" : function( _bMobl ){ 
        var _aE = [].slice.call( doc.querySelectorAll( "[data-lz-src]" ) );
        _aE.filter( function( _e ){
          if( _bMobl ){ // isMobile
            if( _e.dataset.lzM ){ // data-lz-m
              _e.src = _e.dataset.lzSrc;              
            }
          }else{
            _e.src = _e.dataset.lzSrc;
          }
         }); 
      }
    }
})( document );
// You then call fLazy.init(), on intersection, setTimeOut or first Click.

I am sharing a simple lazy loader that I wrote in JS. This works but at the time of this writing Google Lighthouse was pretty buggy in auditing lazy loads, so be patient.

I've updated so that it now can process a sub-set of images based on a isMobile switch. Also, I believe that the Lighthouse extension v3.2 is a bit more stable, so try that.