Post

hasUAVisualTransition landed in Firefox 149, making it available across all major engines. As well as having a very catchy name, it lets you avoid doubling up on page transitions. Here's how it works:

Isn't it the first official API exposing "UA" as a term outside of spec texts? (There is the UA-client-hints being incubated, but I don't consider it official).

Yes I was referring to the initialism "UA". I remember I had a few complaints over some of my stackoverflow answers where I used the initialism without using the full form at all, and I think someone also complained about such use in the HTML specs, hence I now treat it as not obvious for everyone.