JSPM

Cypress is a next generation front end testing tool built for the modern web

AngularJS mocks for testing

Test'em 'scripts! Javascript Unit testing made easy.

Automated browser testing for the modern web development stack.

simple browser testing

Testing infrastructure

Browser utilities to stabilize visual testing with Argos.

Easy to use Node.js based end-to-end testing solution for web applications using the W3C WebDriver API.

An in-memory implementation of webextension-polyfill for testing. Supports all test frameworks (Vitest, Jest, etc)

Insanely fast, full-stack, headless browser testing using Node.js

web-component-tester makes testing your web components a breeze!

Browser testing/automation utilities with async/await

A library to install stable Chromium for testing via Gauge and Taiko

Automatically opens your browser and iOS Simulator to preview Node.js email messages sent with Nodemailer. Made for Forward Email and Lad. Cross-browser and cross-platform email testing.

Proxies browserify's require in order to allow overriding dependencies during testing.

Lightweight client testing framework

Serenity/JS Screenplay Pattern library offering a flexible, web driver-agnostic approach for interacting with web-based user interfaces and components, suitable for various testing contexts

DappDriver is an e2e testing framework designed for testing decentralized applications (dApps) using MetaMask, Rainbow or Zerion

AI-powered natural language end-to-end testing framework

Automated browser testing for the modern web development stack.

Common utilities and helpers to make testing assertions easier

Cross browser testing for your ember-cli app using SauceLabs.

Easy e2e browser testing in Node

a simple, full-featured, JavaScript testing framework

A universal testing suite that works with Mocha style test runners _and_ Node.js's built-in test runner.

Playwright (Cross-browser testing framework) provider for Nest.js

A fake REST server that can run as a service or bundled within a browser, for testing and demoing

A powerful Jest + Puppeteer E2E testing framework with built-in device automation, data builders, and CLI

Bellini mocks for testing

A modern testing tool that makes Playwright easy to use with simple YAML syntax

Cypress.io end to end testing tool

async testing framework for es-modules

Template plugin for mocking and testing

Simple performance testing tool using SauceLabs

This method returns the index of the first element in the array that satisfies the provided testing function.

<div align="center"> <h1>Svelte Testing Library</h1>

Web console reporter for Mocha testing framework

minimal browser mocks for testing react-dom code in node.js

TAP reporters for zora testing library

Playwright utilities for testing and automation

A client for working with the BrowserStack APIs.

tap-producing test harness for node and browsers

A lightweight load testing tool using real browsers for streaming applications with DRM support

Element is a real browser load testing tool

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

Extend Chai Assertion library with tests for http apis

Extends Chai with assertions about promises.

Minimal lightweight logging for JavaScript, adding reliable log level methods to any available console.log methods

JavaScript library for DOM operations

the stream module from node core for browsers

This package contains Microsoft Azure LoadTestingClient client library.

Give your JS App some Backbone with Models, Views, Collections, and Events.

Privacy-friendly conversion tracking and A/B testing script for UserTrax

memlab API

memlab browser E2E interaction libraries

A lightweight, fast browser module for converting HTML to PDF with advanced styling support, customizable options, and comprehensive testing

It is a lightweight rest client for node.js and the browser

Render React components in Vitest Browser Mode

Automated Functional Testing (AFT) package supporting UI testing in browsers

Utilities.

An AI powered browser automation testing agent powered by LLMs.

[](https://percy.io/f1364dca/eBay-Skin)

Mocha tests in Electron.

Automated Functional Testing (AFT) package supporting UI testing in browsers with support for BrowserStack, Sauce Labs and Local Selenium Grid

Cypress.io end to end testing tool

Make End-to-End Testing Great for Once

A responsiveness testing tool on browsers

A lightweight wrapper making assertion testing much easier.

expressive server-side functional testing with jQuery and jsdom

A JavaScript testing framework for the real world

The string_decoder module from Node core

Adapter that integrates @serenity-js/web with Protractor, enabling Serenity/JS reporting and using the Screenplay Pattern to write end-to-end test scenarios

Provides a minified version of selected `@sa11y` libraries to be injected into a browser (using webdriver) and executed from integration testing workflows.

Adapter that integrates @serenity-js/web with Playwright, enabling Serenity/JS reporting and using the Screenplay Pattern to write component and end-to-end test scenarios

Array#isArray for older browsers

Browser-friendly inheritance fully compatible with standard node.js inherits()

Auto mock all localstorage and sessionstorage APIs for your Jest tests

Cypress.io end to end testing tool

Node.js Buffer API, for the browser

Event based JavaScript for the browser

Render Vue components in Vitest Browser Mode

Converts a source-map from/to different formats and allows adding/changing properties.

ES2015 `Object.assign()` ponyfill

Modern and minimalist testing library for the web

Extends Chai with assertions for the Sinon.JS mocking framework.

Automated browser testing for the modern web development stack.

The Node.js `util.deprecate()` function with browser support

Open stuff like URLs, files, executables. Cross-platform.

A proper monster for front-end automated testing

Determine if an object is a Buffer

Run TAP unit tests in 1789+ browsers

OpenTelemetry Core provides constants and utilities shared by all OpenTelemetry SDK packages.

Serenity/JS test runner adapter for Playwright Test, combining Playwright's developer experience with the advanced reporting and automation capabilities of Serenity/JS

All-in-one open source e2e testing framework, with low-code recorder, runner + batteries built-in.

strings comparison matchers for chai

A library for parsing IPv4 and IPv6 IP addresses in node and the browser.

Render Svelte components in Vitest Browser Mode

Public logs API for OpenTelemetry

An ES2015 mostly-spec-compliant `Reflect.getPrototypeOf` sham/polyfill/replacement that works in as many engines as possible

Public API for OpenTelemetry

Base class for node which OpenTelemetry instrumentation modules extend

Flood Element is a browser based load generation tool for easily testing modern web application performance

Utilities.

Use Ky in both Node.js and browsers

Detect Browser, Engine, OS, CPU, and Device type/model from User-Agent & Client Hints data. Supports browser & node.js environment

JavaScript's functional programming helper library.

Universal WHATWG Fetch API for Node, Browsers and React Native

in memory localStorage polyfill for node.js utilizing ES6 proxies

High performance (de)compression in an 8kB package

Microsoft Azure SDK for JavaScript - Aborter

the path module from node core for browsers

Lightweight browser detector

JWA, JWS, JWE, JWT, JWK, JWKS for Node.js, Browser, Cloudflare Workers, Deno, Bun, and other Web-interoperable runtimes

Media-Mock is a JavaScript library that simulates media devices (like webcams) in web applications, allowing developers to test and debug media constraints, device configurations, and stream functionality without needing physical devices. This is particul

Convert a typed array to a Buffer without a copy

A powerful command-line interface for automating Chrome browser using Playwright. Perfect for web scraping, automation, testing, and browser workflows.

Library to work against complex domain names, subdomains and URIs.

atob for Node.JS and Linux / Mac / Windows CLI (it's a one-liner)

Better `os.arch()` for node and the browser -- detect OS architecture

Parse and stringify URL query strings

<!-- markdownlint-disable MD024 -->

Check which JavaScript environment your code is running in at runtime: browser, Node.js, Bun, etc

Utility for mocking XMLHttpRequest.

Super simple browser testing influenced by testling and smokestack

Get the bundle identifier of the default browser (macOS). Example: com.apple.Safari

A simple, lightweight JavaScript API for handling cookies

Exports a jsdom window object.

The assert module from Node.js, for the browser.

Get the default browser

HTML5 `FormData` for Browsers and Node.

https module compatability for browserify

Decode JWT tokens, mostly useful for browser applications.

A better opn. Reuse the same tab on Chrome for 👨‍💻.

Parse milliseconds into an object

Random number generator for browsers and node.js

Chai plugin for JSON Schema v4

JSON without touching any globals

E2E Testing Reinvented with AI - A powerful TypeScript browser automation framework using AI-powered testing with LangChain, OpenAI GPT-4o, and Playwright

the tty module from node core for browsers

vm module for the browser

node's constants module for the browser

Compare semver version strings to find greater, equal or lesser.

Isomorphic implementation of WebSocket

timers module for browserify

Node's domain module for the web browser. This is merely an evented try...catch with the same API as node, nothing more.

A polyfill for the Resize Observer API

Lazy assertions without performance penalty

btoa for Node.JS (it's a one-liner)

Collection of samples useful in testing IOTA modules.

Microsoft Azure SDK for JavaScript - Logger

Chromium binaries for Node.js projects

Promisify an event by waiting for it to be emitted

Evaluate Javascript in PhantomJS, and print the output.

Toggle current selected content in browser

Copy stuff into clipboard using JS with fallbacks

Converts a Web-API readable-stream into a Node.js readable-stream.

resolve which handles browser field support in package.json

Auto mock all localstorage and sessionstorage APIs for your Vitest tests

An alias package for `crypto.randomBytes` in Node.js and/or browsers

Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.

OpenTelemetry Zipkin Exporter allows the user to send collected traces to Zipkin.

OpenTelemetry Collector Trace Exporter allows user to send collected traces to the OpenTelemetry Collector

High Level DOM Assertions for QUnit

Isomorphic client library for supporting long-running operations in node.js and browser.

React Browser Tests is a browser first testing library. The tests are written in React and run in a browser. Terminal also works.

Apple's property list parser/builder for Node.js and browsers

Get a KeyboardEvent.key-style string from an event

Framework-agnostic, micro-library for getting stack traces in all environments

date / time comparison matchers for chai

OAuth 2 / OpenID Connect Client API for JavaScript Runtimes

OpenTelemetry Collector Metrics Exporter allows user to send collected metrics to the OpenTelemetry Collector

Microsoft Azure Storage SDK for JavaScript - Blob

Cross-browser `CustomEvent` constructor

(recursive)? merging of (cloned)? objects.

Check if a value is a natural number

Tiny and elegant HTTP client based on the Fetch API

Check if a value is an `Error` instance

Simple wrapper for cross-browser usage of the JavaScript Fullscreen API, which lets you bring the page or any element into fullscreen.

Isomorphic WebSocket

OpenTelemetry Collector Logs Exporter allows user to send collected logs to the OpenTelemetry Collector

JavaScript SVG parser and renderer on Canvas.

DOM assertions for the Chai assertion library using vanilla JavaScript

Adapter that integrates @serenity-js/web with the latest stable version of WebdriverIO, enabling Serenity/JS reporting and using the Screenplay Pattern to write web and mobile test scenarios

The Backbone Framework

The node.js assert module, re-packaged for web browsers.

Detects where the current browser extension code is being run. Compatible with Firefox, Chrome and derivates.

UMD __dirname and __filename browser shim

Spies for the Chai assertion library.

🔥 An extremely fast and efficient LRU cache for JavaScript with high compatibility (including Browsers) — 6.8KB.

LRU and FIFO caches for Client or Server

Lightweight and performant natural sorting of arrays and collections by differentiating between unicode characters, numbers, dates, etc.

Serializes any DOM node into a String

Low-Level OAuth 2 / OpenID Connect Client API for JavaScript Runtimes

Topological sort of directed acyclic graphs (like dependecy lists)

An implementation of https://github.com/emberjs/rfcs/pull/726

React's ExecutionEnvironment module extracted for use in other packages & components

Shallow deep equal assertion for chai

Dynamic script loading for browser

A JavaScript library to zip and unzip files in the browser, Deno and Node.js

HKDF with no dependencies using runtime's native crypto

browser-side require() the node way

Plugin for loglevel message prefixing

A tool to get browser's scrollbars width.

A package that contains an array of every single file extension there is for text files

DOMParser.parseFromString for XML with IE8 fallback

Extends Chai with lint-friendly terminating assertions.

Tests if ES6 Symbol is supported.

All-in-one open source e2e testing framework, with low-code recorder, runner + batteries built-in.

A package that contains an array of every single file extension there is for binary files

A framework for mocking the FileMaker webviewer window object for developing and testing fm webviewer apps in browser.

Check whether operating system CPU architecture is 64-bit or 32-bit (Supports browsers)

Tests if ES6 @@toStringTag is supported.

Isomorphic client library for Azure KeyVault's keys.

Smallest/simplest possible means of using btoa with both Node and browserify

Adds console.table method that prints an array of objects as a table in console

walk the dependency graph to generate json output that can be fed into browser-pack

A tiny (230B) and fast UUID (v4) generator for Node and the browser

Determine if a filename and/or buffer is text or binary. Smarter detection than the other solutions.

Creates an async iterator for a variety of inputs in the browser and node. Supports fetch, node-fetch, and cross-fetch

sort module-deps output for deterministic browserify bundles

Array#filter for older browsers.

Check in which environment the code is running - browser/node.js/webworker/jsdom/deno

LambdaTest Rest Client for Node.js

The simplest unit testing framework possible.

A generated SDK for WebSiteManagementClient.

Detect default web browser of the current user, cross-platform (Win/Lin/Mac)

Unpack a browser type and version from the useragent string

Simple JS stack with auto run for node and browsers

Image structural similarity (SSIM). In TypeScript/JavaScript. For browser/server.

Smart IPFS gateway selector with latency testing and fallback logic (vanilla JS)

XMLHttpRequest emulation for node.js

Light-weight EventEmitter (less than 1KB when gzipped)

A browser and nodeJS compatible plugin that allows to generate GraphQL Queries and Variables

Simulates a global browser environment using jsdom

A mock browser with window, document, location, navigation, local and session storage to use for client side code tests in a node environment.

Browser compatibility data provided by MDN Web Docs

Node standard library for browser.

pack node-style source files from a json stream into a browser bundle

A high-performance, lightweight LRU cache. Built for developers who need fast caching without compromising on features.

JavaScript UI component for displaying audio waveforms

Analyze and debug space usage through source maps

Super light and fast Extensible ES6+ events and EventEmitters for Node and the browser. Easy for any developer level, use the same exact code in node and the browser. No frills, just high speed events!

Flmngr file manager (Local disk / Amazon S3 / Azure Blob)

Get the paths of edge browser easily

Detect device type and render your component according to it

A generated SDK for ResourceManagementClient.

Minimal JavaScript module loader

HMAC-based (HOTP) and Time-based (TOTP) One-Time Password library