JavaScript API for Chrome and Firefox

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

Cypress Documentation for the Cypress App, API, Cypress Cloud, UI Coverage and Cypress Accessibility.

A simple and composable way to validate data in JavaScript (and TypeScript).

Next generation testing framework powered by Vite.

Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.

📗🌐 🚢 Comprehensive and exhaustive JavaScript & Node.js testing best practices (August 2025)