AsyncFunction

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2017.

The AsyncFunction object provides methods for async functions. In JavaScript, every async function is actually an AsyncFunction object.

Note that AsyncFunction is not a global object. It can be obtained with the following code:

js
const AsyncFunction = async function () {}.constructor;

AsyncFunction is a subclass of Function.

Constructor

AsyncFunction()

Creates a new AsyncFunction object.

Instance properties

Also inherits instance properties from its parent Function.

These properties are defined on AsyncFunction.prototype and shared by all AsyncFunction instances.

AsyncFunction.prototype.constructor

The constructor function that created the instance object. For AsyncFunction instances, the initial value is the AsyncFunction constructor.

AsyncFunction.prototype[Symbol.toStringTag]

The initial value of the [Symbol.toStringTag] property is the string "AsyncFunction". This property is used in Object.prototype.toString().

Note: AsyncFunction instances do not have the prototype property.

Instance methods

Inherits instance methods from its parent Function.

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-async-function-objects

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
AsyncFunction
AsyncFunction() constructor

Legend

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Full support
Full support

See also