Autoplay and animation must be stoppable
Aliases: stop autoplay · reduced motion · pause stop hide
What it is
A carousel that starts itself, a looping illustration, a background video: for someone with an attention disability these are not decoration. They are forced attentional capture. Pause, stop, hide requires that moving or auto-updating content can be paused, stopped, or hidden—and that it stays stopped, rather than restarting a few seconds later.
The object of control is whether motion is still stealing attention. It is not whether a session will time out, and it is not whether a flash might trigger a seizure. Unlimited time to read the page does not help if motion keeps pulling the eyes off the text.
Why it happens
The visual system answers transients first. A looping animation keeps minting new transients, blocking habituation, so exogenous attention wins the bout with the current task. One core difficulty in ADHD is exactly this contest: the main content is visible; it cannot hold.
A region that still moves, blinks, scrolls, or auto-refreshes after several seconds turns reading and working-memory maintenance into an interference task. The OS “reduce motion” setting raises the requirement to the system layer; an app that ignores it keeps playing after the user has already said no. Media the user pressed play on is not autoplay; looping that nobody asked for is.
Studying it
In a conformance sample: open the page, take hands off for ten seconds, log every region still looping, then check that each has a control that actually stops it. The control must be keyboard-reachable; after a stop, reload (with OS reduced-motion already on) must not restart it.
Independent variables: duration of motion, whether OS reduced-motion is honoured, distance from the motion to its pause control. Dependent variables: reading errors on the primary task, gaze pulls, whether motion resumes within a fixed interval after pause.
Do not recruit photosensitive people to “see if it triggers.” Flash rate is a different safety criterion. Measure whether attention is hijacked and whether the user can turn the motion off.
Where it stops holding
A video or sign-language clip the user started is content while it plays. One-shot transitions and spinners shorter than a few seconds rarely count as sustained capture. In a game or drawing tool, motion is the task; do not demand a static default, but still offer a way to dampen non-essential ornament. A silent autoplaying background video that cannot be paused still fails; “there is no audio” is not a defence.
Applying it
- Pause motion, scrolling, or auto-update that lasts more than a few seconds by default, or put pause immediately beside it. After pause, do not self-resume.
- Honour the OS reduced-motion preference to kill decorative loops, rather than hiding a second switch that overrides what the user already declared.
- Verify: open the page and do nothing for ten seconds. Every region still looping must be pausable from the keyboard alone. Reload with OS reduced-motion on: decorative loops must not return. Fail if pause is followed by a spontaneous restart.