Binary Counter Animation
Eight bits count upward in binary, each one flipping at half the speed of its right-hand neighbor, with the decimal value beside them. Every bit is one keyframe whose duration doubles.
Also known as: binary number animation, bits counting css, binary clock text.
HTML
<div class="txt-binary-counter" aria-label="Binary counter"> <span class="txt-binary-counter-bits" aria-hidden="true"><i style="--w: 128"></i><i style="--w: 64"></i><i style="--w: 32"></i><i style="--w: 16"></i><i style="--w: 8"></i><i style="--w: 4"></i><i style="--w: 2"></i><i style="--w: 1"></i></span> <b class="txt-binary-counter-dec" aria-hidden="true"></b> </div>
CSS
@property --txt-binary-counter-v {
syntax: "<integer>";
initial-value: 0;
inherits: false;
}
.txt-binary-counter {
--c: var(--txt-color, #3b82f6);
font-size: var(--txt-size, 32px);
font-family: system-ui, sans-serif;
font-weight: 700;
line-height: 1.2;
display: inline-flex;
align-items: center;
gap: 0.45em;
font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
--tick: 0.5s;
/* start from 45 (00101101) instead of zero */
--from: calc(var(--tick) * -45);}
.txt-binary-counter-bits {
display: flex;
gap: 0.1em;
}
.txt-binary-counter-bits i:nth-child(4) {
margin-right: 0.22em;
}
.txt-binary-counter-bits i::before {
content: "0";
display: grid;
place-items: center;
width: 0.95em;
height: 1.3em;
border-radius: 0.18em;
font-style: normal;
animation: txt-binary-counter-bit calc(var(--tick) * 2 * var(--w)) step-end var(--from) infinite;
}
.txt-binary-counter-dec {
width: 5ch;
color: var(--c);
counter-reset: txt-binary-counter-n var(--txt-binary-counter-v);
animation: txt-binary-counter-count calc(var(--tick) * 256) steps(256) var(--from) infinite;
}
.txt-binary-counter-dec::after {
content: "= " counter(txt-binary-counter-n);
}
@keyframes txt-binary-counter-bit {
0%, 49% { content: "0"; color: color-mix(in srgb, var(--c) 55%, transparent); background: color-mix(in srgb, var(--c) 10%, transparent); }
50%, 100% { content: "1"; color: #fff; background: var(--c); }
}
@keyframes txt-binary-counter-count {
to { --txt-binary-counter-v: 256; }
}
@media (prefers-reduced-motion: reduce) {
.txt-binary-counter, .txt-binary-counter *, .txt-binary-counter::before, .txt-binary-counter::after, .txt-binary-counter *::before, .txt-binary-counter *::after {
animation-duration: 0.01ms !important;
animation-iteration-count: 1 !important;
transition-duration: 0.01ms !important;
}
}Customizing this snippet
- Color: set
--txt-coloron the element or a parent. Currently previewing#3b82f6. - Font size: set
--txt-size. Every other dimension is inem, so the whole thing scales together. Currently previewing40px. - 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.