12 CSS Skeleton Loaders

Pulse Block

A simple opacity pulse — minimal, GPU-friendly, and the default style used by the Tailwind animate-pulse utility class.

Pulse Block the 2nd of 12 designs in the 12 CSS Skeleton Loaders collection. The design is implemented in pure CSS — no JavaScript required. Copy the HTML and CSS panels below into your project. Because the demo is pure CSS, it works in any framework or templating engine you happen to use. The design honours prefers-reduced-motion and uses real semantic markup, so it ships accessibility-ready out of the box.

Live preview

The code

<div class="sk-pulse">
  <div class="sk-pulse-bar" style="width: 80%"></div>
  <div class="sk-pulse-bar" style="width: 60%"></div>
  <div class="sk-pulse-bar" style="width: 70%"></div>
</div>

.sk-pulse {
  width: 220px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.sk-pulse-bar {
  height: 12px;
  border-radius: 6px;
  background: #2a2a36;
  animation: skPulse 1.5s ease-in-out infinite;
}
@keyframes skPulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.45;
  }
}

@media (prefers-reduced-motion: reduce) {
  .sk-pulse,
  .sk-pulse * {
    animation: none !important;
  }
}