CSSPropertyRule: syntax 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 syntax property of the CSSPropertyRule interface returns the literal syntax of the custom property registration represented by the @property rule, controlling how the property's value is parsed at computed-value time.

Value

A string.

Examples

This stylesheet contains a single @property rule. The first CSSRule returned will be a CSSPropertyRule representing this rule. The syntax property returns the literal string "<color>".

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

Specifications

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

Browser compatibility