Operable
WCAG 2.3.3
Motion & Animation
Respect prefers-reduced-motion. No auto-playing content that flashes more than 3 times per second. Parallax, scroll-triggered animations, and auto-play video must be pauseable.
In plain terms
Honor the system setting that reduces motion, and let people pause anything that moves — sliding or spinning content can cause nausea or distraction.
Why this matters
Large movement — parallax, auto-playing video, sliding transitions — can cause nausea, dizziness, and migraines for people with vestibular disorders, and pulls focus from people with attention difficulties.
How to detect
Quick check
Turn on your operating system's 'reduce motion' setting and reload: do big animations stop or tone down? Check that anything moving, blinking, or auto-playing can be paused.