Reactive Backgrounds Animation — Reference

Blinking ASCII Dots

The Blinking ASCII Dots is a CSS animation component that fullscreen Braille character grid animated by layered sine wave interference. Mouse proximity distorts the wave field and clicks generate expanding ripple waves. 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.

canvasasciibraillewavesinteractivebackgroundreactivefullscreen
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When to use the Blinking ASCII Dots

Performance characteristics

How it compares

Unlike equivalent JavaScript implementations, the Blinking ASCII Dots 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 TC_HEX = '#555555';
    var DENSITY = 1;
    var SPEED = 0.75;
    var REMOVE_WAVE = true;

    function hexToRgbStr(h) {
      var c = h.charAt(0) === '#' ? h.slice(1) : h;
      return parseInt(c.slice(0,2),16)+', '+parseInt(c.slice(2,4),16)+', '+parseInt(c.slice(4,6),16);
    }
    var TC = hexToRgbStr(TC_HEX);

    var CHARS = '⠁⠂⠄⠈⠐⠠⡀⢀⠃⠅⠘⠨⠊⠋⠌⠍⠎⠏⠑⠒⠓⠔⠕⠖⠗⠙⠚⠛⠜⠝⠞⠟⠡⠢⠣⠤⠥⠦⠧⠩⠪⠫⠬⠭⠮⠯⠱⠲⠳⠴⠵⠶⠷⠹⠺⠻⠼⠽⠾⠿';

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

    function resize() {
      canvas.width = innerWidth;
      canvas.height = innerHeight;
    }

    function waveVal(x, y, t) {
      var w1 = Math.sin(x*0.05+t*0.5)*Math.cos(y*0.05-t*0.3);
      var w2 = Math.sin((x+y)*0.04+t*0.7)*0.5;
      var w3 = Math.cos(x*0.06-y*0.06+t*0.4)*0.3;
      return (w1+w2+w3)/2;
    }

    function clickFx(x, y, now) {
      var tot = 0;
      for (var k=0; k<clickWaves.length; k++) {
        var w = clickWaves[k];
        var age = now-w.t;
        if (age < 5000) {
          var dx = x-w.x, dy = y-w.y;
          var dist = Math.sqrt(dx*dx+dy*dy);
          var rad = age/5000*500, ww = 100;
          if (Math.abs(dist-rad) < ww) {
            tot += (1-age/5000)*w.i*(1-Math.abs(dist-rad)/ww)*Math.sin((dist-rad)*0.05);
          }
        }
      }
      return tot;
    }

    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 draw() {
      var ctx = canvas.getContext('2d');
      time += SPEED*0.016;
      var now = Date.now();
      var W = canvas.width, H = canvas.height;
      var cs = 16/DENSITY;
      var cols = Math.ceil(W/cs), rows = Math.ceil(H/cs);

      ctx.fillStyle = BG;
      ctx.fillRect(0, 0, W, H);
      ctx.font = cs+'px monospace';
      ctx.textAlign = 'center';
      ctx.textBaseline = 'middle';

      for (var row=0; row<rows; row++) {
        for (var col=0; col<cols; col++) {
          var px = col*cs+cs/2, py = row*cs+cs/2;
          var v = waveVal(px, py, time);
          var mf = mouseFx(px, py);
          if (mf > 0) v += mf*Math.sin(time*3)*0.5;
          v += clickFx(px, py, now);
          var nv = (v+1)/2;
          if (Math.abs(v) > 0.15) {
            var ci = Math.min(CHARS.length-1, Math.max(0, Math.floor(nv*CHARS.length)));
            var op = Math.min(0.9, Math.max(0.3, 0.4+nv*0.5));
            ctx.fillStyle = 'rgba('+TC+','+op+')';
            ctx.fillText(CHARS[ci], px, py);
          }
        }
      }

      if (!REMOVE_WAVE) {
        for (var k=0; k<clickWaves.length; k++) {
          var cw2 = clickWaves[k];
          var age2 = now-cw2.t;
          if (age2 < 5000) {
            var p = age2/5000;
            ctx.beginPath();
            ctx.strokeStyle = 'rgba('+TC+','+(1-p)*0.2*cw2.i+')';
            ctx.lineWidth = 1;
            ctx.arc(cw2.x, cw2.y, p*500, 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();
      clickWaves.push({ x: e.clientX-rect.left, y: e.clientY-rect.top, t: Date.now(), i: 2.5 });
      var now = Date.now();
      clickWaves = clickWaves.filter(function(w){ return now-w.t < 5000; });
    });
    canvas.addEventListener('mouseup', function(){ mouse.down = false; });
    draw();
  </script>
</body>
</html>

Frequently asked questions

How do I add the Blinking ASCII Dots 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/blinking-ascii-dots.

Is the Blinking ASCII Dots 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 Blinking ASCII Dots work on mobile browsers?

Yes. The Blinking ASCII Dots 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 Blinking ASCII Dots's colors, speed, or size?

Yes. Open the live customization workspace at grepped.dev/animations/reactive-backgrounds/blinking-ascii-dots 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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