What is Jank?
The short answer
Jank is visible stutter when a page cannot draw frames in time, making scrolling, animation or typing feel choppy.
What people say: “laggy”, “choppy scrolling”, “stutter”.
Jank, explained
It comes from long JavaScript tasks, layout thrashing and heavy paint work; performance profiling in browser DevTools shows exactly where frames are lost.
Questions people ask about Jank
What is Jank?
Jank is visible stutter when a page cannot draw frames in time, making scrolling, animation or typing feel choppy.
Related terms
60 fps means the screen updates sixty times a second, the baseline for motion that looks smooth; each frame has about 16 milliseconds to be ready.
Interaction to Next PaintInteraction to Next Paint measures how quickly a page visibly responds after a tap, click or key press, across the whole visit; good is 200 milliseconds or less.
Page speedPage speed is how quickly a web page loads and becomes usable, measured by metrics like Largest Contentful Paint, Interaction to Next Paint and layout stability.
Core Web VitalsCore Web Vitals are Google's three user-experience metrics: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability.
Part of the Web Encyclopedia by Apex Flow Digital. Definitions are general knowledge, kept current, with no invented statistics.