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WeakRef.prototype.deref()

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 deref() method of WeakRef instances returns this WeakRef's target value, or undefined if the target value has been garbage-collected.

In this article

Syntax

js

deref()

Parameters

None.

Return value

The target value of the WeakRef, which is either an object or a non-registered symbol. Returns undefined if the value has been garbage-collected.

Description

See the Notes on WeakRefs section of the WeakRef page for some important notes.

Examples

Using deref()

See the Examples section of the WeakRef page for the complete example.

js
const tick = () => {
  // Get the element from the weak reference, if it still exists
  const element = this.ref.deref();
  if (element) {
    element.textContent = ++this.count;
  } else {
    // The element doesn't exist anymore
    console.log("The element is gone.");
    this.stop();
    this.ref = null;
  }
};

Specifications

Specification

ECMAScript® 2027 Language Specification
# sec-weak-ref.prototype.deref

Browser compatibility

Enable JavaScript to view this browser compatibility table.

See also

WeakRef

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This page was last modified on Jul 10, 2025 by MDN contributors.

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Standard built-in objects
WeakRef
Constructor
1. WeakRef()
Instance methods
1. deref()
Inheritance
Object/Function
Static methods
Static properties
Instance methods
Instance properties
1. __proto__
2. constructor