Sub-300ms responses make interfaces feel alive; longer ones feel sluggish.

Principles#

Buttons: 150ms color/scale. Reveals: 200–300ms ease-out. Loading: skeleton at 300ms, spinner after 1s. Every microinteraction gets a motion-safe gate.

Applied#

  • Apply it to your next feature, not a mythical redesign
  • Encode the decision as a token or component
  • Write one paragraph of team guidance
  • Audit an existing page against the principle

design/index|Design guides · themes/index|Themes