SmartCJ Support Forum

As you might know webp is a better format for web, but not all browsers support it, you can use <picture tag

for example

<picture>
<source srcset="<!--THUMB_URL-->" type="image/webp">
<source srcset="<!--EXTRA_THUMB_URL-->" type="image/jpeg">
<img src="<!--EXTRA_THUMB_URL-->">
</picture>


You have to create 2 sets of thumbs: main one in webp format, and an extra thumb (see Import - extra options - extra thumb) in jpeg format.