Reduced Motion Check

Introduction

The DeviceHub Reduced Motion Check is a free online prefers-reduced-motion reporter and preview, without installing OS utilities on every laptop, without claiming to diagnose vestibular disorders, and without rewriting other websites’ animation stacks. Motion-sensitive users verifying that Windows, macOS, iOS, or Android reduce-motion toggles reach the browser; frontend engineers confirming matchMedia('(prefers-reduced-motion: reduce)'); QA writing bug reports that separate “OS says reduce” from “site ignores CSS”; educators teaching why autoplaying parallax harms some people; and support desks collecting a one-line preference before escalating all open one HTTPS page and read the media feature the engine exposes. DeviceHub states limits plainly: prefers-* values reflect OS and browser settings, not every assistive technology configuration, not every enterprise policy overlay, and not a medical or clinical assessment of motion sensitivity. This page is not a full accessibility audit, not a WAVE/axe replacement, and not a sitewide animation killer. Pair with Accessibility Preferences for a combined prefers-* overview. Pair with Keyboard Focus Test when animated pages also hide focus rings. Pair with Forced Colors Test when high-contrast themes interact with motion. Pair with Accessibility Preferences and Color Scheme Preference when theme and contrast settings travel with reduce-motion in user reports. Pair with Text Spacing Test when motion-heavy marketing layouts also break under expanded spacing. Pair with Speech Synthesis Test when teams ship read-aloud alternatives beside reduced visual motion, still never a clinical hearing or vestibular exam. Permissions stay none, no camera or microphone is required to read a CSS media query. Schools use Reduced Motion Check to show that honorific CSS is the author’s job; DeviceHub only reveals what the browser currently reports. Capture on the exact browser profile where the bug appears; Incognito without extensions can differ from a daily profile with animation blockers. Corporate MDM images sometimes force reduce-motion while designers test on unlocked laptops that still report no-preference, document the managed profile. Never frame the reduce setting as a clinical diagnosis or fitness certificate, and never claim DeviceHub medically evaluates vestibular health. Never treat a green “preference detected” badge as proof every third-party chatbot widget, embedded map, or Lottie hero complies.

What this tool does

Reduced Motion Check queries prefers-reduced-motion via CSS media / matchMedia, displays reduce versus no-preference, and offers a side-by-side or sequential preview of a sample motion experience versus a reduced alternative so stakeholders see why gating transforms and autoplay matters. It does not disable animations on third-party origins, does not write OS accessibility registries, and does not upload preference telemetry to DeviceHub for advertising when you view the page. Guidance explains that some browsers update live when you flip the OS toggle while others need a refresh, that embedded WebViews may lag, and that “reduce” is a signal for authors, not a guarantee every iframe complies. DeviceHub typed permissions remain none. Users are directed to Accessibility Preferences when they want color-scheme, contrast, and forced-colors beside motion in one hub. The preview never claims to simulate every vestibular trigger, migraine aura, or balance disorder; it is educational UI for product teams, not clinical therapy or occupational health clearance. Closing the tab ends listeners. Notes remind teams that reduced-motion does not equal prefers-reduced-data or save-data, that battery saver modes can independently throttle requestAnimationFrame without changing the media query, and that infinite CSS marquee loops still require author media queries even when DeviceHub correctly shows reduce. When the preview’s reduced path still feels busy, that is a teaching moment about essential versus decorative motion, not a DeviceHub defect and not a medical score.

When to use it

Use Reduced Motion Check after enabling OS reduce-motion, when a marketing page ignores the preference, when writing CSS with @media (prefers-reduced-motion: reduce), when QA needs evidence the browser sees reduce, when teaching inclusive motion design, when onboarding agencies that ship parallax-heavy templates, and when separating user-setting bugs from author CSS bugs. Prefer Accessibility Preferences for a multi-feature snapshot before a release freeze. Prefer Keyboard Focus Test when keyboard users lose visible focus during carousels that also ignore reduce-motion. Prefer Forced Colors Test when high-contrast mode also changes motion-heavy chrome. Prefer Color Scheme Preference when dark theme heroes add extra glow animations. Prefer Color Contrast Checker when reduced static alternatives still fail AA on text. Avoid treating the page as a medical screening for motion sickness, vertigo, or photosensitive epilepsy, flash safety belongs elsewhere and DeviceHub accessibility tools are informational, not clinical. Avoid expecting DeviceHub to patch Shopify themes, WordPress sliders, or app-store WebViews remotely. Retest after OS updates, after switching browsers, after enabling enterprise VDI, and after opening the site inside in-app WebViews. Use in design critiques beside recorded GIFs of the reduced preview. Use before blaming DeviceHub when a single SPA route forgets the media query while the marketing homepage honors it.

How it works

CSS Media Queries Level 5 defines prefers-reduced-motion with values including no-preference and reduce. Browsers map OS accessibility toggles into that feature; DeviceHub reads the result and renders previews locally. Typed permissions stay none. Secure context is standard for DeviceHub hosting. The preference does not enumerate every AT, screen reader verbosity, switch control timing, browser animation flags, and extension-level animation blockers can differ while the media query stays no-preference. iOS Display & Text Size → Motion and Android remove-animations style settings generally flow into Chromium and WebKit; some desktop Linux desktops may leave the query at no-preference even when compositors limit effects, document the desktop environment. Authors should gate non-essential motion, provide reduced alternatives for essential status updates, avoid infinite decorative loops when reduce is set, and still meet keyboard and focus requirements that Reduced Motion Check does not audit. JavaScript matchMedia listeners should react to changes where engines fire them; some older WebViews need a reload, DeviceHub documents both patterns without claiming to fix remote code. DeviceHub will never claim to replace professional audits that review focus order, names, ARIA, and live regions. No server round-trip is required to display the media result. Fingerprinting via reduce-motion is low entropy but real; share qualitative notes when full preference dumps are unnecessary. Compared with speechSynthesis tools in this suite, reduced motion needs no user gesture to speak, reading a media query is passive, while Speech Synthesis Test may require a click before audio. Compared with Color Contrast Checker, this page does not compute WCAG 2.x luminance; pair those jobs intentionally in tickets. Compared with Forced Colors Test, reduce-motion and forced-colors can both be active; capture both rather than collapsing them into one vague “accessibility mode” label.

Step-by-step instructions

1. Open Reduced Motion Check over HTTPS on the device and browser where motion settings are configured.
2. Note whether the page reports reduce or no-preference; flip the OS toggle and refresh if the engine does not update live.
3. Compare the sample motion preview with the reduced preview to brief stakeholders.
4. Open Accessibility Preferences if you also need color-scheme, contrast, and forced-colors in one capture.
5. If focus indicators vanish during animations, continue to Keyboard Focus Test; if High Contrast remaps chrome, open Forced Colors Test.
6. Label results as browser-visible prefers-reduced-motion, not a clinical diagnosis, not a WAVE/axe certificate, and not proof every iframe complies.

Common problems

Site still animates because authors ignore the media query, DeviceHub cannot patch remote CSS. WebView lag after OS toggle. Confusing reduce-motion with battery saver frame throttling. Treating the tool as a vestibular medical test or workplace fitness exam. Expecting WAVE-level page audits from a preference readout. Incognito versus profile differences. Assuming all AT configurations appear in prefers-*. Filing tickets without browser name. Mixing Forced Colors failures into motion bugs. Believing DeviceHub disables TikTok, YouTube, or map tile animations globally. Using the preview as the only acceptance test for complex Lottie or Three.js scenes. Ignoring essential loading indicators that still need a non-animated equivalent. Claiming clinical outcomes from a CSS media feature. MDM profiles that force reduce while designers test unmanaged machines. Extensions that block CSS animations without changing prefers-reduced-motion, creating false “site ignores me” reports. SPA route A honors reduce while route B forgets, hub screenshots alone will not find that without navigation. Confusing prefers-reduced-data with reduced-motion in performance tickets. Expecting DeviceHub to certify photosensitive-safe flash rates, out of scope for this preference tool.

Privacy explanation

Reduced Motion Check reads a CSS media preference already available to any webpage’s stylesheets and displays it locally. DeviceHub does not upload your motion preference for advertising when you use this page. Permissions stay none, no camera, microphone, MIDI, clipboard, or geolocation prompts merely to read matchMedia. Closing the tab stops preview animations. Screenshots are optional, avoid sharing full OS accessibility panels if your organization treats them as sensitive configuration. Results are informational accessibility signals, not medical records or clinical diagnoses of vestibular or neurological conditions. Classroom demos should reset OS toggles after class if shared machines must return to default. Combined with Accessibility Preferences hub rows, motion preference still does not create a health dossier, DeviceHub will not infer diagnoses from media features.