Gradient Progress Bar
A fill that slides in, holds, then sweeps off while a multi-hue gradient flows through it. The hues are rotated from your accent with relative oklch colors, with a color-mix fallback.
Also known as: animated gradient loading bar, rainbow progress bar, colorful progress bar.
HTML
<div class="ldr-gradient-progress-bar" role="progressbar" aria-label="Loading"><span></span></div>
CSS
.ldr-gradient-progress-bar {
--s: var(--ldr-size, 48px);
--c: var(--ldr-color, #3b82f6);
--w: calc(var(--s) * 6);
width: var(--w);
height: calc(var(--s) / 5);
border-radius: var(--s);
background: color-mix(in srgb, var(--ldr-color, #3b82f6) 14%, transparent);
overflow: hidden;
}
.ldr-gradient-progress-bar span {
display: block;
height: 100%;
border-radius: inherit;
background-image: linear-gradient(90deg, var(--c), oklch(from var(--c) l c calc(h + 70)), oklch(from var(--c) l c calc(h + 140)), oklch(from var(--c) l c calc(h + 70)), var(--c));
background-size: var(--w) 100%;
animation:
ldr-gradient-progress-bar-flow 1.4s linear infinite,
ldr-gradient-progress-bar-run 3.2s cubic-bezier(0.65, 0, 0.35, 1) infinite;
}
@supports not (color: oklch(from red l c h)) {
.ldr-gradient-progress-bar span {
background-image: linear-gradient(90deg, var(--c), color-mix(in oklch, var(--c), #ec4899), color-mix(in oklch, var(--c), #f59e0b), color-mix(in oklch, var(--c), #ec4899), var(--c));
}
}
@keyframes ldr-gradient-progress-bar-flow {
to { background-position: var(--w) 0; }
}
@keyframes ldr-gradient-progress-bar-run {
0% { transform: translateX(-100%); }
55%, 72% { transform: translateX(0); }
100% { transform: translateX(100%); }
}
@media (prefers-reduced-motion: reduce) {
.ldr-gradient-progress-bar, .ldr-gradient-progress-bar *, .ldr-gradient-progress-bar::before, .ldr-gradient-progress-bar::after, .ldr-gradient-progress-bar *::before, .ldr-gradient-progress-bar *::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.