Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The CSSPropertyRule interface of the CSS Properties and Values API represents a single CSS @property rule.

CSSRule CSSPropertyRule

Instance properties

Inherits properties from its ancestor CSSRule.

CSSPropertyRule.inherits Read only

Returns the inherit flag of the custom property.

CSSPropertyRule.initialvalue Read only

Returns the initial value of the custom property.

CSSPropertyRule.name Read only

Returns the name of the custom property.

CSSPropertyRule.syntax Read only

Returns the literal syntax of the custom property.

Instance methods

No specific methods; inherits methods from its ancestor CSSRule.


This stylesheet contains a single @property rule. The first CSSRule returned will be a CSSPropertyRule with the properties and values as defined by the rule in CSS.

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


CSS Properties and Values API Level 1
# the-css-property-rule-interface

Browser compatibility

BCD tables only load in the browser