That gif is about 20% faster than how I normally breathe. It stressed me out :)

I made this a while back: https://demos.samgentle.com/breather/

It's a 4-2-6 breathing pattern, but it's a single html file, so should be pretty easy to save and customise if you want something different.

Oh interesting, the latest version of the Wim Hoff app (on Android at least) has that same type of visualization for the breathing coaching!

interesting idea but a slower gif would've been truly relaxing.