vanilla-redued-motion.js

// Grab the prefers reduced media query.
const mediaQuery = window.matchMedia("(prefers-reduced-motion: reduce)");

// Check if the media query matches or is not available.
if (!mediaQuery || mediaQuery.matches) {
  doSomethingWithoutAnimation();
} else {
  doSomethingWithAnimation();
}

// Ads an event listener to check for changes in the media query's value.
mediaQuery.addEventListener("change", () => {
  if (mediaQuery.matches) {
    doSomethingWithoutAnimation();
  } else {
    doSomethingWithAnimation();
  }
});