Radar Sweep
A sweeping beam circles a ringed radar screen and lights up a blip as it passes. A natural fit for search, scanning, syncing and 'looking for devices' states.
Also known as: sonar loader, scanner animation.
HTML
<div class="ldr-radar" role="status" aria-label="Scanning"></div>
CSS
.ldr-radar {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
position: relative;
width: var(--s);
height: var(--s);
border: 1px solid color-mix(in srgb, var(--ldr-color, #3b82f6) 45%, transparent);
border-radius: 50%;
background:
radial-gradient(circle, transparent 0 33%, color-mix(in srgb, var(--ldr-color, #3b82f6) 35%, transparent) 33% calc(33% + 1px), transparent 0 66%, color-mix(in srgb, var(--ldr-color, #3b82f6) 35%, transparent) 66% calc(66% + 1px), transparent 0);
}
.ldr-radar::before {
content: "";
position: absolute;
inset: 0;
border-radius: 50%;
background: conic-gradient(from 0deg, transparent 0 72%, color-mix(in srgb, var(--ldr-color, #3b82f6) 65%, transparent) 100%);
animation: ldr-radar-sweep 2s linear infinite;
}
.ldr-radar::after {
content: "";
position: absolute;
top: 50%;
left: 78%;
width: calc(var(--s) / 9);
height: calc(var(--s) / 9);
margin: calc(var(--s) / -18);
border-radius: 50%;
background: var(--c);
box-shadow: 0 0 calc(var(--s) / 8) var(--c);
animation: ldr-radar-blip 2s ease-out infinite;
}
@keyframes ldr-radar-sweep {
to { transform: rotate(360deg); }
}
@keyframes ldr-radar-blip {
0%, 22% { opacity: 0; }
27% { opacity: 1; }
70%, 100% { opacity: 0; }
}
@media (prefers-reduced-motion: reduce) {
.ldr-radar, .ldr-radar *, .ldr-radar::before, .ldr-radar::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.