There are three categories, with slightly different capabilities and interfaces for each, capped at 15s, 60s, and 3m. The short ones were originally the only ones, 60s became available about a year ago (?), and 3m only just over the summer (and I'm not sure they're even available to all creators yet; they had a slow rollout).

Latest info I could find was 5 minutes max [1], where did you see 15?

[1] https://www.socialmediatoday.com/news/tiktoks-testing-even-l...

I was wrong. It's 5 minutes.

Wow. Thank you. I had no idea about that. I had assumed it would be much, much shorter.

That's very new, though. Even 3 minute videos haven't been around for more than a few months.

Ah I see.

I remember when YouTube had quite a short cap on length years ago (10-15 minutes iirc), which is why I started using vimeo at the time.