Duration
The length of time an animation takes from start to finish, typically measured in milliseconds.
Example usage
“Keep hover feedback under 150ms — at 300ms the interface feels like it’s lagging behind the cursor.”
Editor’s note
Duration should scale with distance and size: small elements moving short distances want 100–200ms, full-screen transitions can hold 300–400ms. Past half a second, motion stops feeling responsive and starts feeling like waiting. When in doubt, shorter.