Mirrored Arcs Spinner
Two arcs open from a single dot, sweep down either side of the ring and pinch back into a dot on the far side while the whole thing turns. One arc is the other mirrored with scaleX(-1).
Also known as: symmetric arc spinner, butterfly spinner, two sided arc loader.
HTML
<svg class="ldr-mirrored-arcs" viewBox="0 0 48 48" role="status" aria-label="Loading"> <circle cx="24" cy="24" r="19" pathLength="100"></circle> <circle cx="24" cy="24" r="19" pathLength="100"></circle> </svg>
CSS
.ldr-mirrored-arcs {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
width: var(--s);
height: var(--s);
animation: ldr-mirrored-arcs-turn 1.4s linear infinite;
}
.ldr-mirrored-arcs circle {
fill: none;
stroke: var(--c);
stroke-width: 4.5;
stroke-linecap: round;
transform-origin: center;
transform: rotate(-90deg);
animation: ldr-mirrored-arcs-sweep 1.4s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}
.ldr-mirrored-arcs circle + circle {
transform: scaleX(-1) rotate(-90deg);
}
/* Each arc runs from the top (0) to the bottom (50); a half turn per loop hands over seamlessly. */
@keyframes ldr-mirrored-arcs-turn {
to { transform: rotate(180deg); }
}
@keyframes ldr-mirrored-arcs-sweep {
0% { stroke-dasharray: 0 100; stroke-dashoffset: 0; }
50% { stroke-dasharray: 42 58; stroke-dashoffset: -6; }
100% { stroke-dasharray: 0 100; stroke-dashoffset: -50; }
}
@media (prefers-reduced-motion: reduce) {
.ldr-mirrored-arcs, .ldr-mirrored-arcs *, .ldr-mirrored-arcs::before, .ldr-mirrored-arcs::after, .ldr-mirrored-arcs *::before, .ldr-mirrored-arcs *::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.