The goal of this page is to show two animation strategies, and monitor the smoothness of each. One is a continuously looping CSS animation of the transform property. The other is a requestAnimationFrame loop which updates the transform property.

The jank checkbox introduces random jank via javascript. On browsers that execute CSS animations on another thread, the jank will affect the responsiveness of javascript but the CSS animation should appear visually smooth. The requestAnimationFrame animation will start to lag behing. A good FPS monitoring API should be able to show this happening.