to-spring-or-not-to-spring

SKILL.md

Easing curves and springs are not interchangeable—they come from different ways of thinking about motion and play different roles in an interface.

Ask: Is this motion reacting to the user, or is the system speaking?

| User-driven (drag, flick, gesture) | Spring | Survives interruption, preserves velocity | | System-driven (state change, feedback) | Easing | Clear start/end, predictable timing | | Time representation (progress, loading) | Linear | 1:1 relationship between time and progress |

Decision framework for choosing between easing curves and springs. Use when implementing animations, debugging motion that feels wrong, or choosing timing functions. Triggers on tasks involving CSS transitions, cubic-bezier, spring physics, gesture animations, or motion library configuration. Source: raphaelsalaja/userinterface-wiki.

View raw