Global objects

Added in: v0.10.0

These objects are available in all modules. The following variables may appear to be global but are not. They exist only in the scope of modules, see the module system documentation:

• __dirname
• __filename
• exports
• module
• require()

The objects listed here are specific to Node.js. There are built-in objects that are part of the JavaScript language itself, which are also globally accessible.

C AbortController

A utility class used to signal cancelation in selected Promise-based APIs. The API is based on the Web API AbortController.

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M abortController.abort([reason])

• reason any An optional reason, retrievable on the AbortSignal's reason property.

Triggers the abort signal, causing the abortController.signal to emit the 'abort' event.

M abortController.signal

Added in: v15.0.0, v14.17.0

• Type: AbortSignal

C AbortSignal

Added in: v15.0.0, v14.17.0

• Extends: EventTarget

The AbortSignal is used to notify observers when the abortController.abort() method is called.

Static method: AbortSignal.abort([reason])

• reason: any
• Returns: AbortSignal

Returns a new already aborted AbortSignal.

Static method: AbortSignal.timeout(delay)

Added in: v17.3.0, v16.14.0

• delay number The number of milliseconds to wait before triggering the AbortSignal.

Returns a new AbortSignal which will be aborted in delay milliseconds.

E 'abort'

Added in: v15.0.0, v14.17.0

The 'abort' event is emitted when the abortController.abort() method is called. The callback is invoked with a single object argument with a single type property set to 'abort':

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The AbortController with which the AbortSignal is associated will only ever trigger the 'abort' event once. We recommended that code check that the abortSignal.aborted attribute is false before adding an 'abort' event listener.

Any event listeners attached to the AbortSignal should use the { once: true } option (or, if using the EventEmitter APIs to attach a listener, use the once() method) to ensure that the event listener is removed as soon as the 'abort' event is handled. Failure to do so may result in memory leaks.

M abortSignal.aborted

Added in: v15.0.0, v14.17.0

• Type: boolean True after the AbortController has been aborted.

M abortSignal.onabort

Added in: v15.0.0, v14.17.0

• Type: Function

An optional callback function that may be set by user code to be notified when the abortController.abort() function has been called.

M abortSignal.reason

Added in: v17.2.0, v16.14.0

• Type: any

An optional reason specified when the AbortSignal was triggered.

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M abortSignal.throwIfAborted()

Added in: v17.3.0, v16.17.0

If abortSignal.aborted is true, throws abortSignal.reason.

C Blob

Added in: v18.0.0

See Blob.

C Buffer

Added in: v0.1.103

• Function

Used to handle binary data. See the buffer section.

C ByteLengthQueuingStrategy

Added in: v18.0.0

A browser-compatible implementation of ByteLengthQueuingStrategy.

M __dirname

This variable may appear to be global but is not. See __dirname.

M __filename

This variable may appear to be global but is not. See __filename.

M atob(data)

Added in: v16.0.0

Global alias for buffer.atob().

M BroadcastChannel

Added in: v18.0.0

See BroadcastChannel.

M btoa(data)

Added in: v16.0.0

Global alias for buffer.btoa().

M clearImmediate(immediateObject)

Added in: v0.9.1

clearImmediate is described in the timers section.

M clearInterval(intervalObject)

Added in: v0.0.1

clearInterval is described in the timers section.

M clearTimeout(timeoutObject)

Added in: v0.0.1

clearTimeout is described in the timers section.

C CompressionStream

Added in: v18.0.0

A browser-compatible implementation of CompressionStream.

M console

Added in: v0.1.100

• Object

Used to print to stdout and stderr. See the console section.

C CountQueuingStrategy

Added in: v18.0.0

A browser-compatible implementation of CountQueuingStrategy.

M Crypto

A browser-compatible implementation of Crypto. This global is available only if the Node.js binary was compiled with including support for the node:crypto module.

M crypto

A browser-compatible implementation of the Web Crypto API.

M CryptoKey

A browser-compatible implementation of CryptoKey. This global is available only if the Node.js binary was compiled with including support for the node:crypto module.

M CustomEvent

A browser-compatible implementation of the CustomEvent Web API.

C DecompressionStream

Added in: v18.0.0

A browser-compatible implementation of DecompressionStream.

M Event

A browser-compatible implementation of the Event class. See EventTarget and Event API for more details.

M EventTarget

A browser-compatible implementation of the EventTarget class. See EventTarget and Event API for more details.

M exports

This variable may appear to be global but is not. See exports.

M fetch

A browser-compatible implementation of the fetch() function.

Class FormData

A browser-compatible implementation of FormData.

M global

Added in: v0.1.27

• Object The global namespace object.

In browsers, the top-level scope is the global scope. This means that within the browser var something will define a new global variable. In Node.js this is different. The top-level scope is not the global scope; var something inside a Node.js module will be local to that module.

Class Headers

A browser-compatible implementation of Headers.

M MessageChannel

Added in: v15.0.0

The MessageChannel class. See MessageChannel for more details.

M MessageEvent

Added in: v15.0.0

The MessageEvent class. See MessageEvent for more details.

M MessagePort

Added in: v15.0.0

The MessagePort class. See MessagePort for more details.

M module

This variable may appear to be global but is not. See module.

M PerformanceEntry

Added in: v19.0.0

The PerformanceEntry class. See PerformanceEntry for more details.

M PerformanceMark

Added in: v19.0.0

The PerformanceMark class. See PerformanceMark for more details.

M PerformanceMeasure

Added in: v19.0.0

The PerformanceMeasure class. See PerformanceMeasure for more details.

M PerformanceObserver

Added in: v19.0.0

The PerformanceObserver class. See PerformanceObserver for more details.

M PerformanceObserverEntryList

Added in: v19.0.0

The PerformanceObserverEntryList class. See PerformanceObserverEntryList for more details.

M PerformanceResourceTiming

Added in: v19.0.0

The PerformanceResourceTiming class. See PerformanceResourceTiming for more details.

M performance

Added in: v16.0.0

The perf_hooks.performance object.

M process

Added in: v0.1.7

• Object

The process object. See the process object section.

M queueMicrotask(callback)

Added in: v11.0.0

• callback Function Function to be queued.

The queueMicrotask() method queues a microtask to invoke callback. If callback throws an exception, the process object 'uncaughtException' event will be emitted.

The microtask queue is managed by V8 and may be used in a similar manner to the process.nextTick() queue, which is managed by Node.js. The process.nextTick() queue is always processed before the microtask queue within each turn of the Node.js event loop.

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C ReadableByteStreamController

Added in: v18.0.0

A browser-compatible implementation of ReadableByteStreamController.

C ReadableStream

Added in: v18.0.0

A browser-compatible implementation of ReadableStream.

C ReadableStreamBYOBReader

Added in: v18.0.0

A browser-compatible implementation of ReadableStreamBYOBReader.

C ReadableStreamBYOBRequest

Added in: v18.0.0

A browser-compatible implementation of ReadableStreamBYOBRequest.

C ReadableStreamDefaultController

Added in: v18.0.0

A browser-compatible implementation of ReadableStreamDefaultController.

C ReadableStreamDefaultReader

Added in: v18.0.0

A browser-compatible implementation of ReadableStreamDefaultReader.

M require()

This variable may appear to be global but is not. See require().

M Response

A browser-compatible implementation of Response.

M Request

A browser-compatible implementation of Request.

M setImmediate(callback[, ...args])

Added in: v0.9.1

setImmediate is described in the timers section.

M setInterval(callback, delay[, ...args])

Added in: v0.0.1

setInterval is described in the timers section.

M setTimeout(callback, delay[, ...args])

Added in: v0.0.1

setTimeout is described in the timers section.

M structuredClone(value[, options])

Added in: v17.0.0

The WHATWG structuredClone method.

M SubtleCrypto

A browser-compatible implementation of SubtleCrypto. This global is available only if the Node.js binary was compiled with including support for the node:crypto module.

M DOMException

Added in: v17.0.0

The WHATWG DOMException class. See DOMException for more details.

M TextDecoder

Added in: v11.0.0

The WHATWG TextDecoder class. See the TextDecoder section.

C TextDecoderStream

Added in: v18.0.0

A browser-compatible implementation of TextDecoderStream.

M TextEncoder

Added in: v11.0.0

The WHATWG TextEncoder class. See the TextEncoder section.

C TextEncoderStream

Added in: v18.0.0

A browser-compatible implementation of TextEncoderStream.

C TransformStream

Added in: v18.0.0

A browser-compatible implementation of TransformStream.

C TransformStreamDefaultController

Added in: v18.0.0

A browser-compatible implementation of TransformStreamDefaultController.

M URL

Added in: v10.0.0

The WHATWG URL class. See the URL section.

M URLSearchParams

Added in: v10.0.0

The WHATWG URLSearchParams class. See the URLSearchParams section.

M WebAssembly

Added in: v8.0.0

• Object

The object that acts as the namespace for all W3C WebAssembly related functionality. See the Mozilla Developer Network for usage and compatibility.

C WritableStream

Added in: v18.0.0

A browser-compatible implementation of WritableStream.

C WritableStreamDefaultController

Added in: v18.0.0

A browser-compatible implementation of WritableStreamDefaultController.

C WritableStreamDefaultWriter

Added in: v18.0.0

A browser-compatible implementation of WritableStreamDefaultWriter.