JSDOM

jsdom is a JavaScript implementation of the WHATWG DOM and HTML standards designed to run in the Node.js environment. It provides a browser-like DOM API by simulating a window and a document, allowing developers to parse HTML and manipulate the DOM without a real browser. A typical usage involves creating a JSDOM instance from an HTML string or a file, after which code can interact with document, window, and related APIs as if running in a web page.

The library aims to offer a practical, browser-compatible environment for server-side JavaScript. It exposes standard DOM features such as document, window, querySelector, addEventListener, and element APIs, along with common Web APIs like localStorage and cookies. It can execute scripts in the DOM when configured with appropriate options and can load external resources via a resource loader, though with notable limitations compared to a real browser. While substantial, its implementation focuses on DOM manipulation and HTML parsing rather than rendering or layout.

Limitations include the absence of actual CSS rendering and visual layout, no real browser rendering or user interaction, and incomplete support for certain browser-specific features. Performance characteristics and security models differ from those of real browsers, and some web platform APIs may be partially supported or missing.

jsdom is widely used for testing, server-side rendering, and automation tasks in Node.js. It is an open-source project distributed via npm and maintained by a community of contributors, serving as a practical substitute for DOM manipulation in non-browser environments and complementing testing frameworks and build workflows.