About this page
Pick an effect: it is applied to the same live HTML form drawn inside the canvas, and the form stays usable through it. An effect that has a demo action plays it once when you pick it (not when you prefer reduced motion); its actions are the buttons in the panel (handle.trigger).
The effects host, the plugins and the frame cap are extensions of this library, not part of the HTML-in-Canvas proposal; they run over the polyfill and over a browser's own implementation (details). Link to one effect with ?effect=<name>; &demo=0 opens it without the showcase.
The readout above the canvas counts the effectframe events of the last second: frames per second, and the interval between frames (median and 95th percentile). At rest an effect that is not continuous by design presents nothing, so it reads 0.
mode: starting
effect: starting
display: measuring
prefers-reduced-motion: -