Reactive Backgrounds Animation — Reference
Flowing Ribbons
The Flowing Ribbons is a CSS animation component that a deformable grid of lines that flows and undulates like fabric. Mouse movement and clicks create ripple distortions that spread through the mesh. It ships as self-contained HTML and CSS with no external dependencies, making it drop-in ready for any modern web project regardless of framework or build system.
When to use the Flowing Ribbons
- Full-bleed hero sections, modal backdrops, and page wrappers
- Component libraries and design systems that need consistent motion patterns
- Progressive enhancement — works in all modern browsers, degrades gracefully
Performance characteristics
- GPU-accelerated — uses CSS transform and opacity so compositing happens off the main thread
- Zero JavaScript dependency in most configurations — no framework, no bundler required
- Approximately 60 fps on any device that supports CSS animations (Chrome 43+, Firefox 16+, Safari 9+)
- Self-contained in a single HTML file — no npm install, no build step, paste and ship
How it compares
Unlike equivalent JavaScript implementations, the Flowing Ribbons does not require any runtime library — there is nothing to install, bundle, or load asynchronously.
Compared to animated GIFs or video embeds, this CSS component is resolution-independent, theme-able via CSS custom properties, and weighs a fraction of the equivalent media file.
Source code
CSS
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { width: 100%; height: 100%; overflow: hidden; background: #F0EEE6; }
canvas { display: block; width: 100%; height: 100%; }HTML
<canvas id="c"></canvas>Full source
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { width: 100%; height: 100%; overflow: hidden; background: #F0EEE6; }
canvas { display: block; width: 100%; height: 100%; }
</style>
</head>
<body>
<canvas id="c"></canvas>
<script>
var BG = '#F0EEE6';
var LC = '#777777';
var SPEED = 0.3;
var REMOVE_WAVE = true;
var canvas = document.getElementById('c');
var time = 0;
var mouse = { x: 0, y: 0, down: false };
var disturbances = [];
function resize() {
var dpr = window.devicePixelRatio || 1;
canvas.width = innerWidth * dpr;
canvas.height = innerHeight * dpr;
canvas.style.width = innerWidth + 'px';
canvas.style.height = innerHeight + 'px';
var ctx = canvas.getContext('2d');
ctx.setTransform(1,0,0,1,0,0);
ctx.scale(dpr, dpr);
}
function mouseFx(x, y) {
var d = Math.sqrt((x-mouse.x)*(x-mouse.x)+(y-mouse.y)*(y-mouse.y));
return Math.max(0, 1-d/200);
}
function disturbFx(x, y, now) {
var tot = 0;
for (var k=0; k<disturbances.length; k++) {
var d = disturbances[k];
var age = now-d.t;
if (age < 3000) {
var dx = x-d.x, dy = y-d.y;
var dist = Math.sqrt(dx*dx+dy*dy);
var rad = age/3000*400, w = 80;
if (Math.abs(dist-rad) < w) tot += (1-age/3000)*d.i*(1-Math.abs(dist-rad)/w)*Math.sin((dist-rad)*0.1);
}
}
return tot;
}
function deform(x, y, t, progress, now) {
var mf = mouseFx(x, y);
var df = disturbFx(x, y, now);
var w1 = Math.sin(progress*Math.PI*4+t*0.01)*30;
var w2 = Math.sin(progress*Math.PI*7-t*0.008)*15;
var h = Math.sin(x*0.02+y*0.015+t*0.005)*10;
var mw = mf*Math.sin(t*0.02+progress*Math.PI*2)*20;
var dw = df*Math.sin(t*0.015+progress*Math.PI*3)*25;
return { ox: w1+h+mw+dw, oy: w2+mw*0.5+dw*0.7 };
}
function draw() {
var ctx = canvas.getContext('2d');
time += SPEED;
var now = Date.now();
var W = canvas.clientWidth, H = canvas.clientHeight;
var GD = 80, rw = W*0.85, ro = (W-rw)/2;
ctx.fillStyle = BG;
ctx.fillRect(0, 0, W, H);
ctx.strokeStyle = LC;
ctx.lineWidth = 0.5;
for (var i=0; i<GD; i++) {
var lx = ro+(i/GD)*rw;
ctx.beginPath();
for (var j=0; j<=GD; j++) {
var lp = (j/GD)*1.2-0.1, ly = lp*H;
var ld = deform(lx, ly, time, lp, now);
j===0 ? ctx.moveTo(lx+ld.ox, ly+ld.oy) : ctx.lineTo(lx+ld.ox, ly+ld.oy);
}
ctx.stroke();
}
for (var k=0; k<GD; k++) {
var hp = (k/GD)*1.2-0.1, hy = hp*H;
ctx.beginPath();
for (var m=0; m<=GD; m++) {
var hx = ro+(m/GD)*rw;
var hd = deform(hx, hy, time, hp, now);
m===0 ? ctx.moveTo(hx+hd.ox, hy+hd.oy) : ctx.lineTo(hx+hd.ox, hy+hd.oy);
}
ctx.stroke();
}
if (!REMOVE_WAVE) {
for (var di=0; di<disturbances.length; di++) {
var dist2 = disturbances[di];
var age2 = now-dist2.t;
if (age2 < 3000) {
var prog = age2/3000;
ctx.beginPath();
ctx.strokeStyle = 'rgba(100,100,100,'+(1-prog)*0.2*dist2.i+')';
ctx.lineWidth = 2;
ctx.arc(dist2.x, dist2.y, prog*400, 0, Math.PI*2);
ctx.stroke();
ctx.strokeStyle = LC;
ctx.lineWidth = 0.5;
}
}
}
requestAnimationFrame(draw);
}
resize();
window.addEventListener('resize', resize);
canvas.addEventListener('mousemove', function(e) {
var rect = canvas.getBoundingClientRect();
mouse.x = e.clientX-rect.left; mouse.y = e.clientY-rect.top;
});
canvas.addEventListener('mousedown', function(e) {
mouse.down = true;
var rect = canvas.getBoundingClientRect();
disturbances.push({ x: e.clientX-rect.left, y: e.clientY-rect.top, t: Date.now(), i: 2 });
var now = Date.now();
disturbances = disturbances.filter(function(d){ return now-d.t < 3000; });
});
canvas.addEventListener('mouseup', function(){ mouse.down = false; });
draw();
</script>
</body>
</html>Frequently asked questions
How do I add the Flowing Ribbons to my project?
Copy the full source code from the code block on this page. Paste the <style> block into your stylesheet (or a <style> tag in your HTML head) and the HTML markup into your template. No npm install or build step is required — the animation is self-contained. To customize colors, speed, or size, use Grepped's workspace at grepped.dev/animations/reactive-backgrounds/flowing-ribbons.
Is the Flowing Ribbons free to use?
Yes. All Grepped preset animations are free to use in personal and commercial projects. You may copy, modify, and redistribute the code without attribution. The only limitation is that you may not resell the presets themselves as part of a competing animation library.
Does the Flowing Ribbons work on mobile browsers?
Yes. The Flowing Ribbons uses standard CSS animations and transforms that are supported in all modern mobile browsers — Chrome for Android, Safari on iOS 9+, Samsung Internet, and Firefox for Android. Where JavaScript is used for interactivity (e.g. cursor effects), it falls back gracefully on touch devices.
Can I customize the Flowing Ribbons's colors, speed, or size?
Yes. Open the live customization workspace at grepped.dev/animations/reactive-backgrounds/flowing-ribbons to adjust the animation with real-time sliders, color pickers, and toggles — no code required. For deeper changes, the source code uses CSS custom properties (variables) so you can edit them directly in your stylesheet.
Want to customize this animation or generate a new one from a text prompt?
Open in Workspace — it's free