Both GTmetrix and Google PageSpeed Insights will display the warning “Serve images in next-gen formats” if your images are not delivered in WebP or AVIF format.
If that is on purpose and you don’t want to serve WebP or AVIF images, that’s fine, simply ignore the warning. But if you do want to serve WebP or AVIF images, continue reading.
ShortPixel Image Optimizer (SPIO) #
If you use ShortPixel Image Optimizer, please visit the relevant troubleshooting sections in the following articles:
- For WebP: Troubleshooting the WebP delivery
- For AVIF: Troubleshooting the AVIF delivery
ShortPixel Adaptive Images (SPAI) #
If you use ShortPixel Adaptive Images, please visit the relevant troubleshooting sections in the following article: ShortPixel Adaptive Images doesn’t serve WebP images, why is that?
Autoptimize #
When using Autoptimize, you simply need to activate the option “Optimize Images”. That’s enough to serve your images in WebP format, which should get rid of the message “Serve images in next-gen formats”.
If you happen to use ShortPixel Image Optimizer with Autoptimize, make sure to read this one too: I want to start using Autoptimize with ShortPixel Image Optimizer, what should I do?
