Hi @Esther_ISM ,
In the blog environment you can handcode the <picture> tag, so the image can be viewed on safari with the jpeg fallback. It’s a bit tedious to do it that way, but i’m not sure there’s an easier way to do it?
Also this was recently submitted in the ideas board, could be useful functionality for the HubSpot CMS in the futre for supporting webp format.
https://community.hubspot.com/t5/HubSpot-Ideas/Automatic-Resizing-for-webp-Images/idc-p/356504?profile.language=en