I use SPIO with Cloudflare and my WebP or AVIF images aren’t served, why is that?

ShortPixel Image Optimizer can be used to deliver WebP and AVIF images even if a website uses Cloudflare. For this to work, you must have the “Using the <PICTURE> tag syntax” option enabled in Settings > ShortPixel > Advanced, as shown below:

Both sub-options can be used:

You can also use the second option ("Without altering the page code (via .htaccess)"), but in this case you need to consider the following:

• It does not work for websites with Cloudflare's free plan.
• If you have a paid plan from Cloudflare, you need to make sure it supports the Vary  header and is properly configured to deliver WebP and/or AVIF from the same URL based on browser capabilities so that it knows (and caches and delivers accordingly) that there are 2 different files to deliver for the same URL depending on the Accept  header sent by the browser. Here's how to do it.