Smush Pro not delivering next-gen formats in test

Hi Gurus,
Just ran a Hummingbord Test and noticed a poor score for "Serve images in next-gen formats" a 65. I just double checked Smush Pro and all advanced features are enabled, including deliver in next gen formats as well as deliver in correct size. I re-ran smuch pro image check to see if it detected any of the images flagged by performance test, nothing.
So I'm not clear which to believe. Do I believe the settings of Smush Pro which indicate that dynamic sizing and next-gen formats and compression have been applied, or do I believe hummingbird test which seems to be saying that images are not being properly compressed and scaled and delivered in next gen format?
Please advise.

  • Ash
    • WordPress Hacker

    Hello emilio_gagliardi

    The images mentioned in the performance test report, those images are used as background images by your theme. I am afraid, smush CDN can't process the images used in css, as a result those are not converted into webp. WebP images are served only from our CDN.

    For those background images, you can manually convert those into webp and upload again. Here is a service that you can try:

    Have a nice day!


  • emilio_gagliardi
    • The Incredible Code Injector

    Thank you kindly for your elaboration.
    While I understand what you're describing, it seems like a big hole without a clear workflow to solve. What is the WPMU Dev suggested workflow for dealing with background images? Each page has a handful of them so across an entire website there are lots of background images that produce the experience and it sounds like you're saying I need to manually post-process each image, which is the exact opposite of what Smush Pro is supposed to do.

    I look forward to your response.

  • Nithin
    • Support Wizard

    Hi emilio_gagliardi,

    I do understand your concern, at the moment I'm afraid only images served via Smush CDN supports WebP conversion. Smush CDN will only work for images listed inside the img tag of the HTML structure would be out of the box delivered in WebP formats, ie for example:
    <img src="path-to-image">

    For images loaded via other methods, that's via CSS. At the moment, I'm afraid, you'll have to manually upload WebP format images instead of manually uploading jpg, or png images in your website.

    You could use the Web Converter online tool for such actions, as mentioned in the previous reply.

    On the other hand, our Smush Team is working on a new built-in feature to support WebP image support for every instance other than images served via Smush CDN. At the moment I'm afraid we don't have an exact ETA regarding this, but it's in our roadmap with high priority.

    Hoping it would be out soon.

    Kind Regards,

Thank NAME, for their help.

Let NAME know exactly why they deserved these points.

Gift a custom amount of points.