Opting in to 120Hz Animations on iPhone 13 Pro
Indeed, the lack of published documentation meant that everyone assumed that adopting 120Hz would be done automatically by the system. This is how it works on the iPad Pro, which has supported ProMotion since 2017. But for the iPhone 13, high frame rate animation is actually gated twice, firstly by a global
Info.plistkey and secondly by the fact that each individual animation in the codebase will need to be audited and marked as wanting high refresh rate pacing.All apps will see ProMotion benefits when the user is actively interacting with the display and generating touch events, which thankfully means scrolling is always ultra-responsive and fluid across the system.
However, this also puts an onus on developers to meticulously check all the animations in their app and do the code changes where it makes sense. 60 FPS animations in app like Twitter will stick out like a sore thumb if the user has just finished scrolling their timeline at a smooth 120 FPS rate.
