Pebbles shader preview: Huge, smooth glass pebbles, dark as obsidian, with coloured light glowing through them.
ittybitty

Pebbles

Huge, smooth glass pebbles, dark as obsidian, with coloured light glowing through them.

Code

Use as

Copy embed: paste into Webflow, Framer, Squarespace or any HTML · Copy for agent: paste into Cursor or Claude · Copy code: the files for your own build.

For your own build, add pebbles.js, ittybitty-shader.js, runtime.js and pointer.js next to this page. Highlighted values follow the controls.

<!-- Quickest: one element. Size it with CSS; it fills its box. -->
<script type="module" src="./ittybitty-shader.js"></script>
<ittybitty-shader effect="pebbles" style="width: 100%; aspect-ratio: 2 / 1;"></ittybitty-shader>

<!-- Or with JavaScript, for full control: -->
<canvas id="pebbles" aria-hidden="true" style="width: 100%; aspect-ratio: 2 / 1; display: block"></canvas>

<script type="module">
  import { pebbles } from './pebbles.js';

  const canvas = document.getElementById('pebbles');
  const effect = pebbles(canvas, {
    speed: 0.5,
    count: 3,
    size: 1,
    roundness: 0.35,
    clarity: 0.6,
    frost: 0.75,
    refraction: 0.7,
    rim: 0.3,
    grain: 0.12,
    backdrop: [[0, '#01655b'], [0.5, '#5a5646'], [1, '#c42414']],
    glass: '#504a44',
    glowColor: '#a00c06',
    depth: false,
    interactive: true,
    responsiveness: 0.5,
    // Performance
    dpr: 1.5,
    adaptive: true,
  });

  // Later: effect.set(…), effect.pause(), effect.resume(), effect.destroy()
</script>

Details

Big rounded pebbles of dark glass, piled up and cropped by the frame. Light glows through their bodies in deep colour, whatever is behind a pebble shows through it bent and softened by frosting, and thin bright lines trace the rims where light grazes them. They drift, turn and breathe slowly; the pointer nudges them aside and the light follows it.

Payload
10.1 KB brotli for pebbles.js, ittybitty-shader.js, runtime.js and pointer.js, measured at build time.
Resolution
Device pixel ratio capped at 1.5. One pass: each pixel looks through its frontmost pebble at the pebbles behind, evaluated directly rather than read back from a buffer.
Frame rate
Display rate.
When unseen
Stops rendering when the canvas leaves the viewport or the tab is hidden, and resumes where it left off.
Reduced motion
Shows a single still frame. Controls and the pointer still update it.
Layers
Up to five effects fuse into one shader and one draw call. Filters such as dithering and halftone process the layers beneath them.
Browsers
Any browser with WebGL2: Chrome and Edge 56+, Firefox 51+, Safari 15+.
Licence
MIT. Copy it, change it, ship it.