HEIF, same idea as BPG (use HEVC intra-frames as images) but by the HEVC group, and already supported natively by Windows, OSX, iOS and Android.
I for one hope the web will end up adopting the Netflix-backed, AV1-based, and royalty-free AVIF:
People complain that’s a standard and Apple needs to support it.
No difference.
But as others have said, MS is supporting HEIF on Windows too.
There are some licensing issues with it, but if you have HEVC hardware and a license, then you can probably use it.