<img>tags and set the
srcto the largest version of your image needed on your site.
data-em-optimizeattribute to your image tag.
100vw. In some cases this is okay, but for smaller images on your page, you will want to tell the browser how big the image will be rendered on your page in order to select the best image from the source set. You can set this in the
em-optimizeattribute follows the same specification as the HTML Image Element Sizes attribute. A comma separated list of
[(Media Query)] <size>or
<size>. If no sizes are set, the size will default to