Motion Smoothness Test
The box should move smoothly. Stuttering indicates frame drops.
Scrolling Lines Test
Lines should scroll smoothly without tearing or judder.
What to check:
- MacBook Pro 14/16" with ProMotion can reach up to 120 FPS
- Other MacBooks typically show 60 FPS
- Animation should be smooth without stuttering
- FPS should remain stable (not fluctuating wildly)
ProMotion 120Hz not showing?
- Safari caps page rendering at 60 FPS by default
- Safari: Develop menu → Feature Flags (or Experimental Features) → uncheck "Prefer Page Rendering Updates near 60fps", then reload
- Check System Settings → Displays → Refresh Rate is set to "ProMotion"
- Recent Chrome versions support 120Hz on macOS — if FPS stays at 60, try another browser