At EdgeConf 2012,
Facebook confirmed this when it
mentioned that in an A/B test, it slowed
down scrolling from 60fps to 30fps,
causing engagement to collapse.
What is smooth interaction?
Devices refresh their screen 60 times a second.
Thus, frame budget for smooth interaction is 16ms
(1 second / 60 frames = 16.66 ms / frame)
Though, browser has got some householding work as well,
which leaves us with about 10ms in total.
What can cause Jank during scroll?
Processing that consumes more than 16ms:
● Time consuming operations e.g. Garbage Collection event.
● Loads of repainting on the screen, reason can be attributed
to JS / CSS or both.