`paint()` CSS function

The paint() CSS function defines an <image> value generated with a PaintWorklet.

Syntax

paint(workletName, ...parameters)

where:

workletName

The name of the registered worklet.

parameters Optional

Optional additional parameters to pass to the paintWorklet

Formal syntax

<paint()> = 
  paint( <ident>, <declaration-value>? )

Examples

Basic CSS paint() usage

Given the following HTML:

<ul>
  <li>item 1</li>
  <li>item 2</li>
  <li>item 3</li>
  <li>item 4</li>
  <li>item 5</li>
  <li>item 6</li>
  <li>item 7</li>
  <li>item 8</li>
  <li>item 9</li>
  <li>item 10</li>
  <li>item N</li>
</ul>

In JavaScript, we register the paint worklet:

CSS.paintWorklet.addModule(
  "https://mdn.github.io/houdini-examples/cssPaint/intro/worklets/boxbg.js",
);

In the CSS, we define the background-image as a paint() type with the worklet name, boxbg, along with any variables (ex. --box-color and --width-subtractor) the worklet will use:

body {
  font: 1.2em / 1.2 sans-serif;
}
li {
  background-image: paint(boxbg);
  --box-color: hsl(55 90% 60%);
}

li:nth-of-type(3n) {
  --box-color: hsl(155 90% 60%);
  --width-subtractor: 20;
}

li:nth-of-type(3n + 1) {
  --box-color: hsl(255 90% 60%);
  --width-subtractor: 40;
}

CSS paint() with parameters

You can pass optional arguments in the CSS paint() function. In this example, we passed two arguments that control whether the background-image on a group of list items is filled or has a stroke outline, and the width of that outline:

<ul>
  <li>item 1</li>
  <li>item 2</li>
  <li>item 3</li>
  <li>item 4</li>
  <li>item 5</li>
  <li>item 6</li>
  <li>item 7</li>
  <li>item 8</li>
  <li>item 9</li>
  <li>item 10</li>
  <li>item N</li>
</ul>

CSS.paintWorklet.addModule(
  "https://mdn.github.io/houdini-examples/cssPaint/intro/worklets/hilite.js",
);

body {
  font: 1.2em / 1.2 sans-serif;
}

li {
  --box-color: hsl(55 90% 60% / 100%);
  background-image: paint(hollow-highlights, stroke, 2px);
}

li:nth-of-type(3n) {
  --box-color: hsl(155 90% 60% / 100%);
  background-image: paint(hollow-highlights, filled, 3px);
}

li:nth-of-type(3n + 1) {
  --box-color: hsl(255 90% 60% / 100%);
  background-image: paint(hollow-highlights, stroke, 1px);
}

We've included a custom property in the selector block defining a boxColor. Custom properties are accessible to the PaintWorklet.

Specifications

Browser compatibility

See also

• PaintWorkletGlobalScope
• CSS Painting API
• Using the CSS Painting API
• <image>
• Canvas API