Reduced Motion is a system-level accessibility preference, available on major operating systems and mobile platforms, for people who experience discomfort, dizziness, or nausea from animated transitions, parallax scrolling, or auto-playing motion, often related to vestibular disorders or migraine conditions.
Websites can detect this preference through the prefers-reduced-motion CSS media query and respond by disabling or simplifying non-essential animation. Sites that ignore this signal and force full animation regardless of the user’s operating system setting are increasingly treated as a real accessibility gap rather than just a nice-to-have.