CSSPropertyRule: initialValue property

Baseline 2024
Newly available

Since ⁨July 2024⁩, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The read-only initialValue nullable property of the CSSPropertyRule interface returns the initial value of the custom property registration represented by the @property rule, controlling the property's initial value.

Value

A string which is a <declaration-value>.

Examples

This stylesheet contains a single @property rule. The first CSSRule returned will be a CSSPropertyRule representing this rule. The initialValue property returns the string "#c0ffee" this being the value of the initial-value property in the CSS.

css
@property --property-name {
  syntax: "<color>";
  inherits: false;
  initial-value: #c0ffee;
}
js
const myRules = document.styleSheets[0].cssRules;
console.log(myRules[0].initialValue); // "#c0ffee"

Specifications

Specification
CSS Properties and Values API Level 1
# dom-csspropertyrule-initialvalue

Browser compatibility