Pause, stop, hide

Success criterion 2.2.2 covers two kinds of content and asks for one thing. The first kind is anything that moves, blinks, or scrolls by itself for more than five seconds while other content is on the page. The second is anything that updates itself: a live count, a feed that prepends, a figure that refreshes. For both, the reader must be given a way to pause, to stop, or to hide it, and the control has to be reachable without leaving what they were doing. Five seconds is the whole of the exemption: a short entrance animation is fine, and a carousel that has rotated three times while somebody was reading the paragraph beside it is not.

The reason is not motion sensitivity, though the two overlap. It is that moving content beside static content steals attention on a loop, and auto-updating content moves the thing a reader was in the middle of reading. Someone using screen magnification loses their place when the layout reflows under them; someone reading slowly loses the sentence every time the carousel turns. Stopping is enough. The criterion asks for an escape, not for a transport bar, and a single visible Pause that actually stops everything is a complete answer.

This is worth keeping apart from prefers-reduced-motion, which is often offered as though it discharged the duty. A preference is a standing request, made once in a system setting, that a person carries to every site. A pause control is an escape offered in the moment, on this page, for content that is moving right now. Honouring the preference is necessary and it does not cover the reader who has no such preference and simply wants the thing to stop. Nor does an endlessly looping pulse animation get a pass for being small: it blinks, it does not stop, and if there is text next to it, it is in scope.

The uncomfortable case for this site is its own attract mode. A specimen that plays itself, on a loop, beside an article somebody is reading, is precisely the content this criterion exists for, which is why every stage carries a visible play control that stops the script, why the stage pauses when it leaves the viewport, and why a stated motion preference turns attract off entirely rather than merely slowing it down.