WeakRef() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

The WeakRef() constructor creates WeakRef objects.

Syntax

js
new WeakRef(target)

Note: WeakRef() can only be constructed with new. Attempting to call it without new throws a TypeError.

Parameters

target

The target value the WeakRef should refer to (also called the referent). Must be an object or a non-registered symbol.

Return value

A new WeakRef object referring to the given target value.

Exceptions

TypeError

Thrown if target is not an object or a non-registered symbol.

Examples

Creating a new WeakRef object

See the main WeakRef page for a complete example.

js
class Counter {
  constructor(element) {
    // Remember a weak reference to a DOM element
    this.ref = new WeakRef(element);
    this.start();
  }
}

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-weak-ref-constructor

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
WeakRef() constructor

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also