index.html

---
title: structuredClone()
slug: Web/API/structuredClone
tags:
  - API
  - DOM
  - Method
  - NeedsCompatTable
  - Reference
  - structuredClone
browser-compat: api.structuredClone
---
<div>{{APIRef("HTML DOM")}}</div>

<p>The global <strong><code>structuredClone()</code></strong> method deep clones a given value using the <a href="/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm">structured clone algorithm</a>.</p>

<h2 id="Syntax">Syntax</h2>

<pre class="brush: js">const <var>clonedValue</var> = structuredClone(<var>value</var>[, { <var>transfer</var> }]);
</pre>

<h3 id="Parameters">Parameters</h3>

<dl>
  <dt><code><var>value</var></code></dt>
  <dd>The value to be cloned. This can be any <a
    href="/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm">structured-clonable
    type</a>.</dd>
    <dt><code><var>transfer</var></code> {{optional_inline}}</dt>
    <dd>A sequence of objects that are <a
        href="/en-US/docs/Web/API/Transferable">transferred</a> with value. The
      ownership of these objects is transfered from the input value to the cloned value
      that is returned.</dd>
  </dl>

<h3 id="Return_value">Return value</h3>

<p>The returned <code><var>clonedValue</var></code> is a clone of the original passed
  <code><var>value</var></code>, with transfered values for items passed in the
  <code><var>transfer</var></code> array.</p>

<h2>Description</h2>

<p>This function can be used to deep copy JavaScript values. The structured clone algorithm
  also supports circular references. The below example demonstrates this:</p>

<pre class="brush: js">// Create an object with a value and a circular reference to itself.
const original = { name: "MDN" };
original.itself = original;

// Clone it
const clone = self.structuredClone(original);

console.assert(clone !== original); // object are not the same (not same identity)
console.assert(clone.name === "MDN"); // they do have the same values
console.assert(clone.itself === clone); // and the circular reference is preserved
</pre>

<h2 id="Specifications">Specifications</h2>

<p>{{Specifications}}</p>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<p>{{Compat}}</p>

<h2 id="See_also">See also</h2>

<ul>
  <li><a
    href="/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm">Structured clone algorithm</a></li>
</ul>