X3Photo Gallery Forums

I am not quite sure what you mean here by "support" in this context. Although we could easily add support for upload of HEIC (or ANY) format (if you need to make files of this type available for some reason), there is no logical reason to assume this will be an image extension that can be used in X3 "gallery".

• I can't see that this format is supported by ANY browsers. It looks like it's a native iOS format used in iOS apps.
• If some browsers supported it, and you asked "how about use it for browsers that support it", in best case scenario, you would end up having to upload copies of BOTH jpg and HEIC files, and you would end up with a duplicate image-cache in two formats, generally slowing down your website and making cache much less effective.
• Even Google's new format webp, which has been available for years, is still struggling to be adopted. However, this seems the most likely "modern" web-image format to succeed JPG if anything does.

Short story, HEIC is not a web browser image format. If it aims to become one (which doesn't seem to be it's main intention), it will take many years for it to get adopted, if it gets adopted at all (in browser context).