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.

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

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

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

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

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

A client for working with the BrowserStack APIs.

tap-producing test harness for node and browsers

☕ 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.

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

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

JavaScript library for DOM operations

Cypress.io end to end testing tool

the stream module from node core for browsers

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

memlab API

memlab browser E2E interaction libraries

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.

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

expressive server-side functional testing with jQuery and jsdom

Utilities.

A promise controlled browser ideal for testing

Make End-to-End Testing Great for Once

A proper monster for front-end automated testing

Render Vue components in Vitest Browser Mode

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

Cypress.io end to end testing tool

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

Servant reporter module for jasmine in browsers testing module.

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

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

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

Array#isArray for older browsers

Auto mock all localstorage and sessionstorage APIs for your Jest tests

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

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

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

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

Mocha tests in Electron.

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

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

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

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

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

Determine if an object is a Buffer

Servant testing module for jasmine tests running in web browser.

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

Automated browser testing for the modern web development stack.

Use Ky in both Node.js and browsers

Base class for node which OpenTelemetry instrumentation modules extend

Run TAP unit tests in 1789+ browsers

Public API for OpenTelemetry

strings comparison matchers for chai

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

Universal WHATWG Fetch API for Node, Browsers and React Native

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

Public logs API for OpenTelemetry

in memory localStorage polyfill for node.js utilizing ES6 proxies

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

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

HTML5 `FormData` for Browsers and Node.

A simple, lightweight JavaScript API for handling cookies

JavaScript's functional programming helper library.

An AI web browsing framework focused on simplicity and extensibility.

Lightweight browser detector

Microsoft Azure SDK for JavaScript - Aborter

Utilities.

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

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

Cypress.io end to end testing tool

Element is a real browser load testing tool

Random number generator for browsers and node.js

Browser running for Vitest using your browser of choice

the path module from node core for browsers

High performance (de)compression in an 8kB package

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

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

Convert a typed array to a Buffer without a copy

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

Get the default browser

Chai plugin for JSON Schema v4

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

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

Utility for mocking XMLHttpRequest.

Parse and stringify URL query strings

<!-- 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.

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

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

Exports a jsdom window object.

Performance testing library

Microsoft Azure SDK for JavaScript - Logger

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

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

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

Parse milliseconds into an object

node's constants module for the browser

Cypress.io end to end testing tool

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.

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

the tty module from node core for browsers

https module compatability for browserify

vm module for the browser

Isomorphic implementation of WebSocket

Auto mock all localstorage and sessionstorage APIs for your Vitest tests

JSON without touching any globals

timers module for browserify

resolve which handles browser field support in package.json

A polyfill for the Resize Observer API

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

Copy stuff into clipboard using JS with fallbacks

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

Toggle current selected content in browser

JavaScript SVG parser and renderer on Canvas.

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

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

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

Tiny and elegant HTTP client based on the Fetch API

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

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

High Level DOM Assertions for QUnit

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

Check if a value is an `Error` instance

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

Cross-browser `CustomEvent` constructor

Microsoft Azure Storage SDK for JavaScript - Blob

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).

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

Check if a value is a natural number

date / time comparison matchers for chai

OAuth 2 / OpenID Connect Client API for JavaScript Runtimes

Evaluate Javascript in PhantomJS, and print the output.

Chromium binaries for Node.js projects

DOM assertions for the Chai assertion library using vanilla JavaScript

The Backbone Framework

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.

Serializes any DOM node into a String

LRU and FIFO caches for Client or Server

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.

Dynamic script loading for browser

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

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

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

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

Shallow deep equal assertion for chai

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

Extends Chai with lint-friendly terminating assertions.

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

simplify visual regression testing with screenshot capture and compare

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

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

browser-side require() the node way

Plugin for loglevel message prefixing

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

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

A lightweight wrapper making assertion testing much easier.

A lightweight, flexible and based testing library for JS

HKDF with no dependencies using runtime's native crypto

Browser navigation command for Vitest browser mode

DOMParser.parseFromString for XML with IE8 fallback

Isomorphic WebSocket

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

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

Get the paths of edge browser easily

A tool to get browser's scrollbars width.

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

Topological sort of directed acyclic graphs (like dependecy lists)

testing tools for brookjs applications

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

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

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

Detect device type and render your component according to it

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

Tests if ES6 Symbol is supported.

sort module-deps output for deterministic browserify bundles

CSS base styles

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

UMD __dirname and __filename browser shim

File manager plugin for CKEditor 5

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

Tests if ES6 @@toStringTag is supported.

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

Isomorphic client library for Azure KeyVault's keys.

Array#filter for older browsers.

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

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

Unpack a browser type and version from the useragent string