motion

Motion is the most abused tool in interface work because it is the most visible. This skill exists to make you write less of it, and to make what remains correct.

Before writing a line

Answer these in order. Each gate can end the task with zero code, and that is a good outcome.

1. How often will they see it?

Seen	Rule
Every few seconds (typing, list navigation, hover on rows)	Nothing, or under 120ms and barely visible
Many times a day (menus, palettes, tabs, toggles)	Fast feedback only, 120–200ms, no delight
A few times a day (dialogs, drawers, sheets, toasts)	Full entrance and exit, 180–320ms
Rarely (onboarding, success, first run)	The only place a longer, expressive animation belongs

Keyboard-initiated actions are instant. ⌘K, Escape, j/k, tab switching by shortcut: render the new state on the same frame. Motion here reads as latency.