Web/JavaScript/Reference/Global objects/Object/getPrototypeOf

The Object.getPrototypeOf() method returns the prototype (i.e. the value of the internal Web/JavaScript/Reference/Global objects/Object/Prototype property) of the specified object.

Syntax

Object.getPrototypeOf(obj)

Parameters

obj: The object whose prototype is to be returned.

Return value

The prototype of the given object. If there are no inherited properties, null is returned.

Examples

Using getPrototypeOf

var proto = {};
var obj = Object.create(proto);
Object.getPrototypeOf(obj) === proto; // true

Non-object coercion

In ES5, it will throw a TypeError exception if the obj parameter isn't an object. In ES2015, the parameter will be coerced to an Object.

Object.getPrototypeOf('foo');
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf('foo');
// String.prototype                  (ES2015 code)

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Object.getPrototypeOf' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`getPrototypeOf`	Chrome Full support 5	Edge Full support 12	Firefox Full support 3.5	IE Full support 9	Opera Full support 12.1	Safari Full support 5	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 12.1	Safari iOS Full support 5	Samsung Internet Android Full support 1.0	nodejs Full support Yes

Legend

Full support: Full support

Opera-specific notes

Even though older Opera versions don't support Object.getPrototypeOf() yet, Opera supports the non-standard __proto__ property since Opera 10.50.