Sound Wave Loader
Nine rounded bars shaped like a voice waveform, pulsing outward from the tallest bar in the middle. Suits voice input, calls and audio processing. The stagger comes from one --d distance variable.
Also known as: audio wave animation, voice wave bars, mirrored bars loader.
HTML
<div class="ldr-sound-wave" role="status" aria-label="Loading"> <span style="--h: 0.3; --d: 4"></span> <span style="--h: 0.5; --d: 3"></span> <span style="--h: 0.7; --d: 2"></span> <span style="--h: 0.86; --d: 1"></span> <span style="--h: 1; --d: 0"></span> <span style="--h: 0.86; --d: 1"></span> <span style="--h: 0.7; --d: 2"></span> <span style="--h: 0.5; --d: 3"></span> <span style="--h: 0.3; --d: 4"></span> </div>
CSS
.ldr-sound-wave {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
display: flex;
align-items: center;
gap: calc(var(--s) / 14);
height: var(--s);
}
.ldr-sound-wave span {
width: calc(var(--s) / 14);
height: calc(var(--s) * var(--h));
border-radius: var(--s);
background: var(--c);
animation: ldr-sound-wave-pulse 1.1s cubic-bezier(0.45, 0, 0.55, 1) infinite;
animation-delay: calc(var(--d) * 0.13s - 1.1s);
}
@keyframes ldr-sound-wave-pulse {
0%, 100% { transform: scaleY(0.3); opacity: 0.55; }
50% { transform: scaleY(1); opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
.ldr-sound-wave, .ldr-sound-wave *, .ldr-sound-wave::before, .ldr-sound-wave::after, .ldr-sound-wave *::before, .ldr-sound-wave *::after {
animation-duration: 3s;
}
}Customizing this loader
- Color: set
--ldr-coloron the element or a parent. Currently previewing#3b82f6. - Size: set
--ldr-size. Every dimension in the snippet is derived from it. Currently previewing64px. - Speed: change the duration on the
animationshorthand. Delays on the children are relative, so they keep their rhythm. - Accessibility: the root carries
role="status"and anaria-labelso screen readers announce the wait. The reduced-motion rule at the end slows the animation for users who asked for less motion.