AV1 and AVIF

AVIF support was added to chrome in 2020 and inital AV1 support wayyy back in 2018! 

Even if discord used less efficient but faster presets the new support would satisfy most people using AVIF, at least allowing us to share our images or to embed links to AVIF images from the web.

Please join the 72% of browser support in your servers, the desktop app can already display AVIF images, you can see that if you try to upload an imge, it will display until you hit send.