I made a check of our website with Google Pagespeed. Google give the recommendation to use one of this image formats: WebP, JPEG XR and JPEG2000.
Pagespeed Link: https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fm.zukunftsblick.ch%2F
Do you support this? And is this meaningful?
Greetings
Bettina Lucas
Here is my site Read-Only: LINK
(how to share your site Read-Only link)