Image Scaling

<img sizes="(min-width: 1200px) 730w,
            (max-width: 1199px) 610w,
            (max-width: 380px) 350w"
     srcset="/img/blog/responsive-images-lg.png 730w,
             /img/blog/responsive-images-md.png 610w,
             /img/blog/responsive-images-sm.png 350w"
     src="/img/blog/reponsive-images.png"
     alt="responsive images">

https://www.keycdn.com/blog/optimize-images-for-web