[arjie]

I went to see a video I'd uploaded to Youtube a while ago and it's now a short. I have no idea how it became a youtube short. Either I grandpa'd it or they upgrade all vertical form video to shorts.

https://www.youtube.com/shorts/qc5PKbJ3tq4

Entirely possible it's the former.

[max-m]

They have been “upgrading” old videos to shorts for more than a year. As far as I know it once started with videos with a runtime of at most 30 seconds. At some point that was increased to 3 minutes. I think they do this to square and portrait videos, maybe the check is as simple as “height >= width and duration <= 3 minutes”?