Class:AbortController#

A utility class used to signal cancelation in selectedPromise-based APIs.The API is based on the Web API<AbortController>.

const ac =newAbortController();ac.signal.addEventListener('abort',() =>console.log('Aborted!'),                           {once:true });ac.abort();console.log(ac.signal.aborted);// Prints truecopy

const ac =newAbortController();// Use either the onabort property...ac.signal.onabort =() =>console.log('aborted!');// Or the EventTarget API...ac.signal.addEventListener('abort',(event) => {console.log(event.type);// Prints 'abort'}, {once:true });ac.abort();copy

const ac =newAbortController();ac.abort(newError('boom!'));console.log(ac.signal.reason);// Error: boom!copy

Class:Blob#

See<Blob>.

Class:Buffer#

• Type:<Function>

Used to handle binary data. See thebuffer section.

Class:ByteLengthQueuingStrategy#

A browser-compatible implementation ofByteLengthQueuingStrategy.

__dirname#

This variable may appear to be global but is not. See__dirname.

__filename#

This variable may appear to be global but is not. See__filename.

atob(data)#

Global alias forbuffer.atob().

An automated migration is available (source):

npx codemod@latest @nodejs/buffer-atob-btoacopy

Class:BroadcastChannel#

See<BroadcastChannel>.

btoa(data)#

Global alias forbuffer.btoa().

clearImmediate(immediateObject)#

clearImmediate is described in thetimers section.

clearInterval(intervalObject)#

clearInterval is described in thetimers section.

clearTimeout(timeoutObject)#

clearTimeout is described in thetimers section.

Class:CloseEvent#

A browser-compatible implementation of<CloseEvent>. Disable this APIwith the--no-experimental-websocket CLI flag.

Class:CompressionStream#

A browser-compatible implementation ofCompressionStream.

console#

• Type:<Object>

Used to print to stdout and stderr. See theconsole section.

Class:CountQueuingStrategy#

A browser-compatible implementation ofCountQueuingStrategy.

Class:Crypto#

A browser-compatible implementation of<Crypto>. This global is availableonly if the Node.js binary was compiled with including support for thenode:crypto module.

crypto#

A browser-compatible implementation of theWeb Crypto API.

Class:CryptoKey#

A browser-compatible implementation of<CryptoKey>. This global is availableonly if the Node.js binary was compiled with including support for thenode:crypto module.

Class:CustomEvent#

A browser-compatible implementation of<CustomEvent>.

Class:DecompressionStream#

A browser-compatible implementation ofDecompressionStream.

ErrorEvent#

A browser-compatible implementation of<ErrorEvent>.

Class:Event#

A browser-compatible implementation of theEvent class. SeeEventTarget andEvent API for more details.

Class:EventSource#

A browser-compatible implementation of<EventSource>.

Class:EventTarget#

A browser-compatible implementation of theEventTarget class. SeeEventTarget andEvent API for more details.

exports#

This variable may appear to be global but is not. Seeexports.

fetch#

A browser-compatible implementation of thefetch() function.

const res =awaitfetch('https://nodejs.org/api/documentation.json');if (res.ok) {const data =await res.json();console.log(data);}copy

The implementation is based uponundici, an HTTP/1.1 clientwritten from scratch for Node.js. You can figure out which version ofundici is bundledin your Node.js process reading theprocess.versions.undici property.

fetch(url, {dispatcher:newMyAgent() });copy

import { setGlobalDispatcher }from'undici';setGlobalDispatcher(newMyAgent());copy

Class:File#

See<File>.

Class:FormData#

A browser-compatible implementation of<FormData>.

global#

• Type:<Object> The global namespace object.

In browsers, the top-level scope has traditionally been the global scope. Thismeans thatvar something will define a new global variable, except withinECMAScript modules. In Node.js, this is different. The top-level scope is notthe global scope;var something inside a Node.js module will be local to thatmodule, regardless of whether it is aCommonJS module or anECMAScript module.

Class:Headers#

A browser-compatible implementation of<Headers>.

localStorage#

A browser-compatible implementation oflocalStorage. Data is storedunencrypted in the file specified by the--localstorage-file CLI flag.The maximum amount of data that can be stored is 10 MB.Any modification of this data outside of the Web Storage API is not supported.Disable this API with the--no-webstorage (or its alias--no-experimental-webstorage) CLI flag.localStorage data is not stored per user or per request when used in the contextof a server, it is shared across all users and requests.

Class:MessageChannel#

TheMessageChannel class. SeeMessageChannel for more details.

Class:MessageEvent#

A browser-compatible implementation of<MessageEvent>.

Class:MessagePort#

TheMessagePort class. SeeMessagePort for more details.

module#

This variable may appear to be global but is not. Seemodule.

Class:Navigator#

A partial implementation of theNavigator API.

navigator#

A partial implementation ofwindow.navigator.

console.log(`This process is running on${navigator.hardwareConcurrency} logical processors`);copy

console.log(`The preferred language of the Node.js instance has the tag '${navigator.language}'`);copy

console.log(`The preferred languages are '${navigator.languages}'`);copy

console.log(`This process is running on${navigator.platform}`);copy

console.log(`The user-agent is${navigator.userAgent}`);// Prints "Node.js/21"copy

// Request an exclusive lockawait navigator.locks.request('my_resource',async (lock) => {// The lock has been acquired.console.log(`Lock acquired:${lock.name}`);// Lock is automatically released when the function returns});// Request a shared lockawait navigator.locks.request('shared_resource', {mode:'shared' },async (lock) => {// Multiple shared locks can be held simultaneouslyconsole.log(`Shared lock acquired:${lock.name}`);});// Request an exclusive locknavigator.locks.request('my_resource',async (lock) => {// The lock has been acquired.console.log(`Lock acquired:${lock.name}`);// Lock is automatically released when the function returns}).then(() => {console.log('Lock released');});// Request a shared locknavigator.locks.request('shared_resource', {mode:'shared' },async (lock) => {// Multiple shared locks can be held simultaneouslyconsole.log(`Shared lock acquired:${lock.name}`);}).then(() => {console.log('Shared lock released');});copy

Class:PerformanceEntry#

ThePerformanceEntry class. SeePerformanceEntry for more details.

Class:PerformanceMark#

ThePerformanceMark class. SeePerformanceMark for more details.

Class:PerformanceMeasure#

ThePerformanceMeasure class. SeePerformanceMeasure for more details.

Class:PerformanceObserver#

ThePerformanceObserver class. SeePerformanceObserver for more details.

Class:PerformanceObserverEntryList#

ThePerformanceObserverEntryList class. SeePerformanceObserverEntryList for more details.

Class:PerformanceResourceTiming#

ThePerformanceResourceTiming class. SeePerformanceResourceTiming formore details.

performance#

Theperf_hooks.performance object.

process#

• Type:<Object>

The process object. See theprocess object section.

queueMicrotask(callback)#

• callback<Function> Function to be queued.

ThequeueMicrotask() method queues a microtask to invokecallback. Ifcallback throws an exception, theprocess object'uncaughtException'event will be emitted.

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

// Here, `queueMicrotask()` is used to ensure the 'load' event is always// emitted asynchronously, and therefore consistently. Using// `process.nextTick()` here would result in the 'load' event always emitting// before any other promise jobs.DataHandler.prototype.load =asyncfunctionload(key) {const hit =this._cache.get(key);if (hit !==undefined) {queueMicrotask(() => {this.emit('load', hit);    });return;  }const data =awaitfetchData(key);this._cache.set(key, data);this.emit('load', data);};copy

Class:ReadableByteStreamController#

A browser-compatible implementation ofReadableByteStreamController.

Class:ReadableStream#

A browser-compatible implementation ofReadableStream.

Class:ReadableStreamBYOBReader#

A browser-compatible implementation ofReadableStreamBYOBReader.

Class:ReadableStreamBYOBRequest#

A browser-compatible implementation ofReadableStreamBYOBRequest.

Class:ReadableStreamDefaultController#

A browser-compatible implementation ofReadableStreamDefaultController.

Class:ReadableStreamDefaultReader#

A browser-compatible implementation ofReadableStreamDefaultReader.

require()#

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

Class:Response#

A browser-compatible implementation of<Response>.

Class:Request#

A browser-compatible implementation of<Request>.

sessionStorage#

A browser-compatible implementation ofsessionStorage. Data is stored inmemory, with a storage quota of 10 MB.sessionStorage data persists only withinthe currently running process, and is not shared between workers.

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

setImmediate is described in thetimers section.

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

setInterval is described in thetimers section.

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

setTimeout is described in thetimers section.

Class:Storage#

A browser-compatible implementation of<Storage>. Disable this API with the--no-webstorage (or its alias--no-experimental-webstorage) CLI flag.

structuredClone(value[, options])#

The WHATWGstructuredClone method.

Class:SubtleCrypto#

A browser-compatible implementation of<SubtleCrypto>. This global is availableonly if the Node.js binary was compiled with including support for thenode:crypto module.

Class:DOMException#

The WHATWG<DOMException> class.

Class:TextDecoder#

The WHATWGTextDecoder class. See theTextDecoder section.

Class:TextDecoderStream#

A browser-compatible implementation ofTextDecoderStream.

Class:TextEncoder#

The WHATWGTextEncoder class. See theTextEncoder section.

Class:TextEncoderStream#

A browser-compatible implementation ofTextEncoderStream.

Class:TransformStream#

A browser-compatible implementation ofTransformStream.

Class:TransformStreamDefaultController#

A browser-compatible implementation ofTransformStreamDefaultController.

Class:URL#

The WHATWGURL class. See theURL section.

Class:URLPattern#

The WHATWGURLPattern class. See theURLPattern section.

Class:URLSearchParams#

The WHATWGURLSearchParams class. See theURLSearchParams section.

Class:WebAssembly#

• Type:<Object>

The object that acts as the namespace for all W3CWebAssembly related functionality. See theMozilla Developer Network for usage and compatibility.

Class:WebSocket#

A browser-compatible implementation of<WebSocket>. Disable this APIwith the--no-experimental-websocket CLI flag.

Class:WritableStream#

A browser-compatible implementation ofWritableStream.

Class:WritableStreamDefaultController#

A browser-compatible implementation ofWritableStreamDefaultController.

Class:WritableStreamDefaultWriter#

A browser-compatible implementation ofWritableStreamDefaultWriter.