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HighlightRegistry: has() method

Baseline 2025

Newly available

Since ⁨June 2025⁩, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The has() method of the HighlightRegistry interface returns a boolean indicating whether or not a Highlight object with the specified name exists in the registry.

HighlightRegistry is a Map-like object, so this is similar to using Map.has().

Syntax

has(name)

Parameters

name: The name of the Highlight object to test for presence in the registry.

Return value

Returns true if a highlight with the specified name exists in the registry; otherwise false.

Examples

const fooHighlight = new Highlight();
CSS.highlights.set("foo", fooHighlight);

myHighlight.has("foo"); // true
myHighlight.has("bar"); // false

Specifications

Specification
ECMAScript® 2026 Language Specification> # sec-map.prototype.has>

Browser compatibility

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`has`	105	105	140	91	17.2	105	140	72	17.2	20.0	105	17.2