Reactive Backgrounds Animation — Reference

Vertical Bars Noise

The Vertical Bars Noise is a CSS animation component that a canvas-based reactive background with noise-driven horizontal bars that animate, scatter, and ripple in response to mouse movement and clicks. 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.

canvasnoisebarsinteractivebackgroundreactive
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When to use the Vertical Bars Noise

Performance characteristics

How it compares

Unlike equivalent JavaScript implementations, the Vertical Bars Noise 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

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

html
<canvas id="c"></canvas>

Full source

html
<!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 = '#444444';
    var BC = '#000000';
    var LW = 1;
    var SPEED = 0.0005;
    var REMOVE_WAVE = true;

    function hexRgb(h) {
      var c = h.charAt(0) === '#' ? h.slice(1) : h;
      return { r: parseInt(c.slice(0,2),16), g: parseInt(c.slice(2,4),16), b: parseInt(c.slice(4,6),16) };
    }

    var canvas = document.getElementById('c');
    var time = 0;
    var mouse = { x: 0, y: 0, down: false };
    var ripples = [];

    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';
      canvas.getContext('2d').scale(dpr, dpr);
    }

    function noise(x, y, t) {
      var n = Math.sin(x*0.01+t)*Math.cos(y*0.01+t) + Math.sin(x*0.015-t)*Math.cos(y*0.005+t);
      return (n+1)/2;
    }

    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 rippleFx(x, y, now) {
      var tot = 0;
      for (var k=0; k<ripples.length; k++) {
        var r = ripples[k];
        var age = now - r.t;
        if (age < 2000) {
          var dx = x-r.x, dy = y-r.y;
          var dist = Math.sqrt(dx*dx+dy*dy);
          var rad = age/2000*300, w = 50;
          if (Math.abs(dist-rad) < w) tot += (1-age/2000)*r.i*(1-Math.abs(dist-rad)/w);
        }
      }
      return Math.min(tot, 2);
    }

    function draw() {
      var ctx = canvas.getContext('2d');
      time += SPEED;
      var now = Date.now();
      var W = canvas.clientWidth, H = canvas.clientHeight;
      var nLines = Math.floor(H/11);
      var sp = H/nLines;
      var lc = hexRgb(LC), bc = hexRgb(BC);

      ctx.fillStyle = BG;
      ctx.fillRect(0, 0, W, H);

      for (var i=0; i<nLines; i++) {
        var y = i*sp + sp/2;
        var mfy = mouseFx(W/2, y);
        var alpha = Math.max(0.3, 0.3+mfy*0.7);
        ctx.beginPath();
        ctx.strokeStyle = 'rgba('+lc.r+','+lc.g+','+lc.b+','+alpha+')';
        ctx.lineWidth = LW + mfy*2;
        ctx.moveTo(0, y); ctx.lineTo(W, y); ctx.stroke();

        for (var x=0; x<W; x+=8) {
          var nv = noise(x, y, time);
          var mf = mouseFx(x, y);
          var rf = rippleFx(x, y, now);
          var inf = mf+rf;
          var thr = Math.max(0.2, 0.5-mf*0.2-Math.abs(rf)*0.1);
          if (nv > thr) {
            var bw = 3+nv*10+inf*5;
            var bh = 2+nv*3+inf*3;
            var ax = x + Math.sin(time+y*0.0375)*20*nv
              + (mouse.down ? Math.sin(time*3+x*0.01)*10*mf : 0)
              + rf*Math.sin(time*2+x*0.02)*15;
            var inten = Math.min(1, Math.max(0.7, 0.7+inf*0.3));
            ctx.fillStyle = 'rgba('+bc.r+','+bc.g+','+bc.b+','+inten+')';
            ctx.fillRect(ax-bw/2, y-bh/2, bw, bh);
          }
        }
      }

      if (!REMOVE_WAVE) {
        var now2 = Date.now();
        for (var k=0; k<ripples.length; k++) {
          var r2 = ripples[k];
          var age2 = now2 - r2.t;
          if (age2 < 2000) {
            var p2 = age2/2000;
            ctx.beginPath();
            ctx.strokeStyle = 'rgba(100,100,100,'+(1-p2)*0.3*r2.i+')';
            ctx.lineWidth = 2;
            ctx.arc(r2.x, r2.y, p2*300, 0, Math.PI*2);
            ctx.stroke();
          }
        }
      }

      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();
      ripples.push({ x: e.clientX-rect.left, y: e.clientY-rect.top, t: Date.now(), i: 1.5 });
      var now = Date.now();
      ripples = ripples.filter(function(r){ return now-r.t < 2000; });
    });
    canvas.addEventListener('mouseup', function(){ mouse.down = false; });
    draw();
  </script>
</body>
</html>

Frequently asked questions

How do I add the Vertical Bars Noise 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/vertical-bars-noise.

Is the Vertical Bars Noise 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 Vertical Bars Noise work on mobile browsers?

Yes. The Vertical Bars Noise 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 Vertical Bars Noise's colors, speed, or size?

Yes. Open the live customization workspace at grepped.dev/animations/reactive-backgrounds/vertical-bars-noise 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?

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