Wave Sweep
A bright highlight strip travels across the placeholder using a CSS mask — adds a glassy "light passing over" feel without changing the base colour.
Wave Sweep the 5th 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-wave"> <div class="sk-wave-bar" style="width: 80%"></div> <div class="sk-wave-bar" style="width: 95%"></div> <div class="sk-wave-bar" style="width: 65%"></div> </div>
.sk-wave {
width: 220px;
display: flex;
flex-direction: column;
gap: 10px;
}
.sk-wave-bar {
height: 12px;
border-radius: 6px;
background: #2a2a36;
position: relative;
overflow: hidden;
}
.sk-wave-bar::after {
content: "";
position: absolute;
inset: 0;
background: linear-gradient(
90deg,
transparent 0%,
rgba(255, 255, 255, 0.15) 50%,
transparent 100%
);
transform: translateX(-100%);
animation: skWave 1.6s linear infinite;
}
@keyframes skWave {
100% {
transform: translateX(100%);
}
}
@media (prefers-reduced-motion: reduce) {
.sk-wave,
.sk-wave * {
animation: none !important;
}
}