if “Load WebP or AVIF in supported browsers?” is on, .png files with transparency will loose that transparency in browsers that support AVIF due to a recent technical change in Shortpixel’s AVIF toolchain.
Shortpixel is looking at alternative solutions, but until then as a workaround you can either:
add .png to Autoptimize’s lazyload exclusion field
or to use below code snippet to disable AVIF images;
You probably have heard about AVIF already, but if not; it is a new image format which is based on the AV1 video format and generally has superior compression than the better-known WebP, JPEG, PNG and GIF formats. Avif is currently supported by Chrome & Opera and can be enabled by setting the image.avif.enabled flag in Firefox.
So there you have it, AVIF is now available in WordPress!
We’re finalizing work on Autoptimize 2.4 with beta-3, which was just released. There are misc. changes under the hood, but the main functional change is the inclusion of image optimization!
This feature uses Shortpixel’s smart image optimization proxy, where requests for images are routed through their URL and automagically optimized. As the image proxy is hosted on one of the best preforming CDN’s with truly global presence obviously using HTTP/2 for parallelized requests, as the parameters are not in a query-string but are part of the URL and as behind the scenes the same superb image optimization logic is used that can also be found in the existing Shortpixel plugin, you can expect great results from just ticking that “optimize image” checkbox on the “Extra” tab :-)
Image optimization will be completely free during the 2.4 Beta-period. After the official 2.4 release this will remain free up until a still to be defined threshold per domain, after which additional service can be purchased at Shortpixel’s.
If you’re already running AO 2.4 beta-2, you’ll be prompted to upgrade. And if you’d like to join the beta to test image optimization, you can download the zip-file here. The only thing I ask in return is feedback (bugs, praise, yay’s, meh’s, …) ;-)