Split Square Loader
A square cut on its diagonal slides apart along the cut, turns a quarter while open, then snaps shut. Four quarter turns make one loop; the halves are two clip-path triangles on one box.
Also known as: diagonal split loader, sliding triangles loader, slice square animation.
HTML
<div class="ldr-split-square" role="status" aria-label="Loading"><span></span><span></span></div>
CSS
.ldr-split-square {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
position: relative;
width: calc(var(--s) * 0.66);
height: calc(var(--s) * 0.66);
margin: calc(var(--s) * 0.17);
animation: ldr-split-square-turn 3.2s cubic-bezier(0.65, 0, 0.35, 1) infinite;
}
.ldr-split-square span {
--k: 1;
position: absolute;
inset: 0;
background: var(--c);
clip-path: polygon(0 0, 100% 0, 0 100%);
animation: ldr-split-square-slide 0.8s cubic-bezier(0.65, 0, 0.35, 1) infinite;
}
.ldr-split-square span:nth-child(2) {
--k: -1;
background: color-mix(in srgb, var(--c) 58%, #fff);
clip-path: polygon(100% 0, 100% 100%, 0 100%);
}
@keyframes ldr-split-square-slide {
0%, 100% { transform: translate(0, 0); }
30%, 70% { transform: translate(calc(var(--k) * var(--s) * 0.1), calc(var(--k) * var(--s) * -0.16)); }
}
@keyframes ldr-split-square-turn {
0%, 7.5% { transform: rotate(0deg); }
17.5%, 32.5% { transform: rotate(90deg); }
42.5%, 57.5% { transform: rotate(180deg); }
67.5%, 82.5% { transform: rotate(270deg); }
92.5%, 100% { transform: rotate(360deg); }
}
@media (prefers-reduced-motion: reduce) {
.ldr-split-square, .ldr-split-square *, .ldr-split-square::before, .ldr-split-square::after, .ldr-split-square *::before, .ldr-split-square *::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.