Web browsers · Research guidance. Instructions are based on publisher guidance; a UK IPTV account was not tested on this platform.
A preference needs an implementation response
MDN describes prefers-reduced-motion as a way for a website to detect a device preference to reduce non-essential motion. It is a signal available to page code, not a promise that every animation on every page is automatically rewritten. A site’s actual response still needs observation in the relevant browser and view.
Identify the exact movement
Record whether the element is a moving decorative rail, a transition, an animated image or the programme the viewer intentionally started. Different elements can have different controls and purposes. Saying the whole site moves is less useful than naming the element, the device preference and whether a visible pause control affects it.
Check the intended user controls
Use the page’s documented motion or pause control where available and retain the person’s operating-system preference. If a control does not stop the named decorative motion, report that precise result. Do not disable an accommodation as a permanent workaround or assume an interface preference should alter the story’s frame rate or create a static version of every programme.
Describe the evidence conservatively
A source-code media query can show implementation intent, while an observed browser comparison shows actual behaviour in that environment. Neither alone certifies every device or accessibility task. A useful report includes the browser version, narrow or wide view, setting state and the specific element observed, without claiming a universal pass from the presence of one CSS rule.
Questions, answered
Does a device preference prove every site animation will stop?
No. The page must respond and the result must be observed.
Does one CSS rule certify full accessibility?
No. It is one part of a specific implementation.