Morphing Blob Button
A round voice button whose gradient body keeps morphing like a drop of liquid, with a softer blob breathing out of phase behind it. The shape is eight border-radius values animated while it turns.
Also known as: blob button css, voice assistant button, organic shape animation css.
HTML
<button class="btn-morphing-blob" type="button" aria-label="Start voice input"> <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><rect x="9" y="3" width="6" height="11" rx="3"/><path d="M5.5 11a6.5 6.5 0 0 0 13 0M12 17.5V21"/></svg> </button>
CSS
.btn-morphing-blob {
--c: var(--btn-color, #3b82f6);
display: inline-flex;
align-items: center;
justify-content: center;
gap: 0.5em;
padding: 0.75em 1.6em;
border: 0;
border-radius: 0.6em;
font: 600 var(--btn-size, 18px)/1.1 system-ui, sans-serif;
cursor: pointer;
-webkit-tap-highlight-color: transparent;
position: relative;
isolation: isolate;
width: 4.6em;
height: 4.6em;
padding: 0;
border-radius: 50%;
background: transparent;
color: #fff;
transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);}
.btn-morphing-blob::before,
.btn-morphing-blob::after {
content: "";
position: absolute;
inset: 0;
z-index: -1;
border-radius: 42% 58% 62% 38% / 45% 42% 58% 55%;
background: linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 35%, #ec4899));
animation:
btn-morphing-blob-morph 6s ease-in-out infinite,
btn-morphing-blob-turn 12s linear infinite;
}
.btn-morphing-blob::before {
inset: -0.55em;
opacity: 0.3;
animation-duration: 7s, 16s;
animation-direction: alternate, reverse;
}
.btn-morphing-blob svg {
width: 1.7em;
height: 1.7em;
}
.btn-morphing-blob:is(:hover, :focus-visible) { transform: scale(1.06); }
.btn-morphing-blob:active { transform: scale(0.92); }
@keyframes btn-morphing-blob-morph {
0%, 100% { border-radius: 42% 58% 62% 38% / 45% 42% 58% 55%; }
33% { border-radius: 60% 40% 38% 62% / 55% 60% 40% 45%; }
66% { border-radius: 38% 62% 55% 45% / 62% 38% 62% 38%; }
}
@keyframes btn-morphing-blob-turn {
to { transform: rotate(360deg); }
}
@media (prefers-reduced-motion: reduce) {
.btn-morphing-blob, .btn-morphing-blob *, .btn-morphing-blob::before, .btn-morphing-blob::after, .btn-morphing-blob *::before, .btn-morphing-blob *::after {
animation-duration: 0.01ms !important;
animation-iteration-count: 1 !important;
transition-duration: 0.01ms !important;
}
}Customizing this snippet
- Color: set
--btn-coloron the element or a parent. Currently previewing#3b82f6. - Base size: set
--btn-size. Every other dimension is inem, so the whole thing scales together. Currently previewing18px. - Speed: change the duration on the
transitionoranimationshorthand. Staggered delays are relative, so they keep their rhythm. - Reduced motion: the rule at the end of the CSS turns the motion off for people who asked their OS for less of it. Keep it.