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!

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.

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

Browser testing/automation utilities with async/await

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.

a simple, full-featured, JavaScript testing framework

Easy e2e browser testing in Node

Bellini mocks for testing

Lightweight client testing framework

Common utilities and helpers to make testing assertions easier

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

Simple performance testing tool using SauceLabs

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

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

Playwright E2E test helpers for enterprise testing

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

async testing framework for es-modules

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

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

Integration testing for the modern web

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

Playwright utilities for testing and automation

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

tap-producing test harness for node and browsers

A client for working with the BrowserStack APIs.

☕ Latte — Lightweight Flow-Based Testing Framework for real browser testing

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.

This package contains Microsoft Azure LoadTestingClient client library.

TAP reporters for zora testing library

Extend Chai Assertion library with tests for http apis

Render Svelte components in Vitest Browser Mode

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

MCP server for iOS Simulator control and browser automation - unified toolkit for mobile and web testing

Cypress.io end to end testing tool

Extends Chai with assertions about promises.

Template plugin for mocking and testing

Accessibility engine for automated testing of web applications, with focus on interaction.

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

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

Cypress.io end to end testing tool

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

memlab browser E2E interaction libraries

memlab API

MCP server for website testing with Playwright - browser automation, HTML extraction, JavaScript execution, monitoring

Render React components in Vitest Browser Mode

Undetectable browser automation library with Cloudflare bypass and bot detection evasion. Stealth automation for web scraping, automated testing, and undetected browser automation. Built on Chrome CDP.

expressive server-side functional testing with jQuery and jsdom

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

Utilities.

A promise controlled browser ideal for testing

Make End-to-End Testing Great for Once

A simple and small testing suite for javascript, both browser and node.js

Cypress.io end to end testing tool

Render Vue components in Vitest Browser Mode

A proper monster for front-end automated testing

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

Servant reporter module for jasmine in browsers testing module.

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

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

The string_decoder module from Node core

Super simple browser testing influenced by testling and smokestack

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

Event based JavaScript for the browser

The simplest unit testing framework possible.

Node.js Buffer API, for the browser

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

Array#isArray for older browsers

Auto mock all localstorage and sessionstorage APIs for your Jest tests

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

ES2015 `Object.assign()` ponyfill

Promise based HTTP client for the browser and node.js

Mocha tests in Electron.

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

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

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

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

Determine if an object is a Buffer

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

Public API for OpenTelemetry

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

Base class for node which OpenTelemetry instrumentation modules extend

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

Run TAP unit tests in 1789+ browsers

Automated browser testing for the modern web development stack.

Servant testing module for jasmine tests running in web browser.

strings comparison matchers for chai

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

MCP tool for browser inspection, element selection, interactive messaging, and responsive testing

Public logs API for OpenTelemetry

JavaScript's functional programming helper library.

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

Use Ky in both Node.js and browsers

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

in memory localStorage polyfill for node.js utilizing ES6 proxies

Universal WHATWG Fetch API for Node, Browsers and React Native

Utilities.

Lightweight browser detector

Microsoft Azure SDK for JavaScript - Aborter

An AI web browsing framework focused on simplicity and extensibility.

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

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

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

Browser running for Vitest using playwright

Browser running for Vitest using your browser of choice

Element is a real browser load testing tool

Cypress.io end to end testing tool

the path module from node core for browsers

High performance (de)compression in an 8kB package

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

Chai plugin for JSON Schema v4

Convert a typed array to a Buffer without a copy

Get the default browser

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

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

HTML5 `FormData` for Browsers and Node.

A simple, lightweight JavaScript API for handling cookies

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

Utility for mocking XMLHttpRequest.

Parse and stringify URL query strings

Exports a jsdom window object.

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

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

<!-- markdownlint-disable MD024 -->

MCP (Model Context Protocol) server for Chrome automation using Puppeteer. Persistent browser sessions, visual testing, Figma comparison, and design validation. Works seamlessly in WSL, Linux, and macOS.

Random number generator for browsers and node.js

The #1 HTML sanitizer - 100% security success rate AND fastest performance. Outperforms DOMPurify, js-xss, bleach-js and all competitors in comprehensive testing.

Performance testing library

node's constants module for the browser

Parse milliseconds into an object

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

Cypress.io end to end testing tool

resolve which handles browser field support in package.json

Benchmarking tool for testing different browserless configurations

Decode JWT tokens, mostly useful for browser applications.

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

https module compatability for browserify

A JavaScript library for testing webcam and microphone functionality in web browsers

the tty module from node core for browsers

vm module for the browser

JSON without touching any globals

timers module for browserify

Isomorphic implementation of WebSocket

A polyfill for the Resize Observer API

Auto mock all localstorage and sessionstorage APIs for your Vitest tests

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

Microsoft Azure SDK for JavaScript - Logger

Copy stuff into clipboard using JS with fallbacks

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

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

Toggle current selected content in browser

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

An AI powered browser automation testing agent powered by LLMs.

Promisify an event by waiting for it to be emitted

Get a KeyboardEvent.key-style string from an event

Lazy assertions without performance penalty

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

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

Tiny and elegant HTTP client based on the Fetch API

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

High Level DOM Assertions for QUnit

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

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

Microsoft Azure Storage SDK for JavaScript - Blob

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

Cross-browser `CustomEvent` constructor

Check if a value is an `Error` instance

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

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

Check if a value is a natural number

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

JavaScript SVG parser and renderer on Canvas.

OAuth 2 / OpenID Connect Client API for JavaScript Runtimes

date / time comparison matchers for chai

Chromium binaries for Node.js projects

Evaluate Javascript in PhantomJS, and print the output.

The Backbone Framework

DOM assertions for the Chai assertion library using vanilla JavaScript

Dynamic script loading for browser

High level API to add outline to a pdf without any dependency on other programming languages. Works in both browser and node.

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

browser-side require() the node way

Serializes any DOM node into a String

LRU and FIFO caches for Client or Server

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

Render Lit components in Vitest Browser Mode

Testing audio and video codec support in a browser with or without a key system

Spies for the Chai assertion library.

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

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

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

DOMParser.parseFromString for XML with IE8 fallback

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

Extends Chai with lint-friendly terminating assertions.

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

Shallow deep equal assertion for chai

simplify visual regression testing with screenshot capture and compare

Plugin for loglevel message prefixing

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

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

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

A lightweight wrapper making assertion testing much easier.

HKDF with no dependencies using runtime's native crypto

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

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

Browser navigation command for Vitest browser mode

Isomorphic WebSocket

sort module-deps output for deterministic browserify bundles

File manager plugin for CKEditor 5

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

Topological sort of directed acyclic graphs (like dependecy lists)

A tool to get browser's scrollbars width.

testing tools for brookjs applications

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

Tests if ES6 Symbol is supported.

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

CSS base styles

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

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

UMD __dirname and __filename browser shim

Tests if ES6 @@toStringTag is supported.

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

Array#filter for older browsers.

Isomorphic client library for Azure KeyVault's keys.

OpenTelemetry instrumentation for fetch http client in web browsers

Unpack a browser type and version from the useragent string

Browser compatibility data provided by MDN Web Docs

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

A lightweight, flexible and based testing library for JS

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

Check if mobile browser.

Secure, robust, and fast API utility library for Angular, React, and Vue. Simplifies API calls, supports mock JSON APIs for testing, and integrates smoothly with modern apps. Includes JWT, LRU cache, streaming, and optional AES-GCM encryption.

Simple JS stack with auto run for node and browsers