Grain shader preview: Static film grain that adds tooth to flat fills and hides gradient banding.
ittybitty

Grain

Static film grain that adds tooth to flat fills and hides gradient banding.

Code

The usage always matches the preview, layers and performance settings included. No build step or package.

Copy embed gives one block to paste into any page or site builder, no setup. For your own code: add grain.js, ittybitty-shader.js, runtime.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="grain" style="position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none"></ittybitty-shader>

<!-- Or with JavaScript, for full control: -->
<div style="position: relative">
  <!-- your content -->
  <canvas id="grain" aria-hidden="true" style="position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none"></canvas>
</div>

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

  const canvas = document.getElementById('grain');
  const effect = grain(canvas, {
    type: 'film',
    amount: 0.35,
    size: 1.2,
    colour: false,
    blend: 'soft-light',
    // Performance
    dpr: 2,
    adaptive: true,
  });

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

Details

A transparent canvas of fine, soft grain that blends onto whatever sits beneath it. It draws once and again only when you change it, so it costs nothing while the page is open.

Payload
4.3 KB brotli for grain.js and ittybitty-shader.js and runtime.js, measured at build time. See the method.
Resolution
Device pixel ratio capped at 2, so grain stays crisp. Size is in CSS pixels at any density.
Frame rate
None. One frame on mount and one per change.
When unseen
Stops rendering when the canvas leaves the viewport or the tab is hidden, and resumes where it left off.
Reduced motion
Nothing to change: grain never moves.
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.