Hi,
Before I get started, I wanted to show you something I noticed which I thought was kinda funny.
One of the image formats I’ve started to make use of in the last couple of years, is WebP, due to the fact it’s a pretty well optimised format that still looks great and now has pretty good support across all major browsers and user agents. The only notable exceptions are older versions of Safari - support was added in Safari 14 - and Internet Explorer which doesn’t support WebP at all and probably won’t. It is however, fully supported in current releases of Chrome, Firefox, Safari, Edge Legacy, Edge Chromium and Opera which I believe covers the vast majority of user agents today.
It’s a really nice format as I’ve found it tends to be a bit smaller and snappier than PNG or JPEG while still retaining a good level of quality. However, just as a safety net, it would also be great if fallback versions of WebP images are created in PNG/JPEG as well, to serve those user agents that choke on WebP.
I don’t think it’d be appropriate to force all previous uploads in other formats (or any future ones) into WebP, just in case something breaks - I’d say the safest option would be to only do conversions from WebP to PNG/JPEG if needed for compatibility reasons. But it would be nice to have more options - especially if it makes it easier to keep images under the upload limits.