[Feature Request] Add prefers-reduced-motion support for all carousel animations

[SIVALANAGASHANKARNIVAS]

Description

While Bootstrap supports prefers-reduced-motion for some animations, it would be helpful to ensure comprehensive coverage across all carousel transition effects.

Current Behavior

Some carousel animations may still play even when users have enabled reduced motion preferences in their OS settings.

Proposed Enhancement

• Audit all carousel CSS transitions and JavaScript animations
• Ensure @media (prefers-reduced-motion: reduce) is consistently applied
• Consider adding a JavaScript API option to programmatically disable animations

Benefits

1. Accessibility: Helps users with vestibular disorders who experience motion sickness
2. WCAG Compliance: Aligns with WCAG 2.1 Success Criterion 2.3.3
3. User Experience: Respects user preferences set at the OS level

Environment

• Bootstrap version: v5.3.x
• Browser: All modern browsers

[julien-deramond]

Hello @SIVALANAGASHANKARNIVAS

I've checked really quickly the CSS code related to the carousels:

See code

.carousel {
  position: relative;
}

.carousel.pointer-event {
  touch-action: pan-y;
}

.carousel-inner {
  position: relative;
  width: 100%;
  overflow: hidden;
}
.carousel-inner::after {
  display: block;
  clear: both;
  content: "";
}

.carousel-item {
  position: relative;
  display: none;
  float: left;
  width: 100%;
  margin-right: -100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  transition: transform 0.6s ease-in-out;
}
@media (prefers-reduced-motion: reduce) {
  .carousel-item {
    transition: none;
  }
}

.carousel-item.active,
.carousel-item-next,
.carousel-item-prev {
  display: block;
}

.carousel-item-next:not(.carousel-item-start),
.active.carousel-item-end {
  transform: translateX(100%);
}

.carousel-item-prev:not(.carousel-item-end),
.active.carousel-item-start {
  transform: translateX(-100%);
}

.carousel-fade .carousel-item {
  opacity: 0;
  transition-property: opacity;
  transform: none;
}
.carousel-fade .carousel-item.active,
.carousel-fade .carousel-item-next.carousel-item-start,
.carousel-fade .carousel-item-prev.carousel-item-end {
  z-index: 1;
  opacity: 1;
}
.carousel-fade .active.carousel-item-start,
.carousel-fade .active.carousel-item-end {
  z-index: 0;
  opacity: 0;
  transition: opacity 0s 0.6s;
}
@media (prefers-reduced-motion: reduce) {
  .carousel-fade .active.carousel-item-start,
  .carousel-fade .active.carousel-item-end {
    transition: none;
  }
}

.carousel-control-prev,
.carousel-control-next {
  position: absolute;
  top: 0;
  bottom: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 15%;
  padding: 0;
  color: #fff;
  text-align: center;
  background: none;
  filter: var(--bs-carousel-control-icon-filter);
  border: 0;
  opacity: 0.5;
  transition: opacity 0.15s ease;
}
@media (prefers-reduced-motion: reduce) {
  .carousel-control-prev,
  .carousel-control-next {
    transition: none;
  }
}
.carousel-control-prev:hover, .carousel-control-prev:focus,
.carousel-control-next:hover,
.carousel-control-next:focus {
  color: #fff;
  text-decoration: none;
  outline: 0;
  opacity: 0.9;
}

.carousel-control-prev {
  left: 0;
}

.carousel-control-next {
  right: 0;
}

.carousel-control-prev-icon,
.carousel-control-next-icon {
  display: inline-block;
  width: 2rem;
  height: 2rem;
  background-repeat: no-repeat;
  background-position: 50%;
  background-size: 100% 100%;
}

.carousel-control-prev-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23fff'%3e%3cpath d='M11.354 1.646a.5.5 0 0 1 0 .708L5.707 8l5.647 5.646a.5.5 0 0 1-.708.708l-6-6a.5.5 0 0 1 0-.708l6-6a.5.5 0 0 1 .708 0'/%3e%3c/svg%3e") /*rtl:url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23fff'%3e%3cpath d='M4.646 1.646a.5.5 0 0 1 .708 0l6 6a.5.5 0 0 1 0 .708l-6 6a.5.5 0 0 1-.708-.708L10.293 8 4.646 2.354a.5.5 0 0 1 0-.708'/%3e%3c/svg%3e")*/;
}

.carousel-control-next-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23fff'%3e%3cpath d='M4.646 1.646a.5.5 0 0 1 .708 0l6 6a.5.5 0 0 1 0 .708l-6 6a.5.5 0 0 1-.708-.708L10.293 8 4.646 2.354a.5.5 0 0 1 0-.708'/%3e%3c/svg%3e") /*rtl:url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23fff'%3e%3cpath d='M11.354 1.646a.5.5 0 0 1 0 .708L5.707 8l5.647 5.646a.5.5 0 0 1-.708.708l-6-6a.5.5 0 0 1 0-.708l6-6a.5.5 0 0 1 .708 0'/%3e%3c/svg%3e")*/;
}

.carousel-indicators {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 2;
  display: flex;
  justify-content: center;
  padding: 0;
  margin-right: 15%;
  margin-bottom: 1rem;
  margin-left: 15%;
}
.carousel-indicators [data-bs-target] {
  box-sizing: content-box;
  flex: 0 1 auto;
  width: 30px;
  height: 3px;
  padding: 0;
  margin-right: 3px;
  margin-left: 3px;
  text-indent: -999px;
  cursor: pointer;
  background-color: var(--bs-carousel-indicator-active-bg);
  background-clip: padding-box;
  border: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  opacity: 0.5;
  transition: opacity 0.6s ease;
}
@media (prefers-reduced-motion: reduce) {
  .carousel-indicators [data-bs-target] {
    transition: none;
  }
}
.carousel-indicators .active {
  opacity: 1;
}

.carousel-caption {
  position: absolute;
  right: 15%;
  bottom: 1.25rem;
  left: 15%;
  padding-top: 1.25rem;
  padding-bottom: 1.25rem;
  color: var(--bs-carousel-caption-color);
  text-align: center;
}

.carousel-dark {
  --bs-carousel-indicator-active-bg: #000;
  --bs-carousel-caption-color: #000;
  --bs-carousel-control-icon-filter: invert(1) grayscale(100);
}

:root,
[data-bs-theme=light] {
  --bs-carousel-indicator-active-bg: #fff;
  --bs-carousel-caption-color: #fff;
  --bs-carousel-control-icon-filter: ;
}

[data-bs-theme=dark] {
  --bs-carousel-indicator-active-bg: #000;
  --bs-carousel-caption-color: #000;
  --bs-carousel-control-icon-filter: invert(1) grayscale(100);
}

There are already some transitions handled with prefers-reduced-motion:

.carousel-indicators [data-bs-target] {
  /* ... */
  transition: opacity 0.6s ease;
}
@media (prefers-reduced-motion: reduce) {
  .carousel-indicators [data-bs-target] {
    transition: none;
  }
}

Are some use cases missing?