The "Using the <PICTURE> tag syntax" option doesn't work; WebP images won't show up

The option " Using the <PICTURE> tag syntax" replaces the img HTML tags with picture tags so ShortPixel can deliver WebP files correctly. We are talking about one of the two options you can use to deliver WebP images on your site. It is located on Settings > ShortPixel > Advanced > Next Generation Images.

There could be a few possible explanations why this delivery method doesn't work:

• The WebP version was not generated. Check this article - I optimized already all the images but then I realized that I didn't select the option to generate WebP, what can I do?
• The images are served via JavaScript mechanisms.
• A cache solution is serving old pages. It can be your browser, your server, your CDN or a cache plugin. Try clearing all of them: How to clear WordPress cache
• You used a page builder for page creation. Our feature may not work well with pages created with some of these tools.
• The images are background images: if your images are loaded via CSS with the property background-image, ShortPixel Image Optimizer will not be able serve them as WebP with this method.
• You've got a Windows Plesk server. You will have to add a MIME type on your server for .webp extensions: image/webp .webp

If none of these is true for your case, then you should try an alternative solution for serving WebP images like:

• Use the second WebP delivery option: Without altering the page code (via .htaccess).
• If you have an NGINX server, you can configure NGINX to transparently serve WebP files when supported.
• Replace ShortPixel Image Optimizer with ShortPixel Adaptive Images.
• Use another plugin to deliver the WebP files created by ShortPixel, like Cache Enabler or WP Rocket.