Node.js
The runtime that takes JavaScript out of the browser and onto the server
Node.js is a free, open-source runtime that lets JavaScript run outside the browser - directly on a server. It powers backend APIs, real-time applications and the build tooling behind most modern websites.
Node.js is a runtime environment that runs JavaScript outside the browser - on servers and desktop machines. Created in 2009 and built on the V8 engine from Google Chrome, it is now stewarded by the OpenJS Foundation. It turned JavaScript, once a browser-only language, into a full server-side technology.
Its defining feature is an asynchronous, event-driven model: instead of pausing while a slow operation (such as a database query) finishes, the server keeps handling other requests in the meantime. This lets a single Node.js process hold thousands of open connections at once. That is why it became a standard choice for real-time products - chat, live notifications, collaborative tools and online dashboards.
Node.js ships with npm (Node Package Manager), the largest registry of ready-made code packages in the world. Developers assemble features such as payment integration, authentication or PDF generation from tested open-source modules instead of writing everything from scratch, which noticeably shortens timelines and budgets.
One more point matters in practice: almost all modern frontend tooling - Next.js, React build systems, the Tailwind CSS compiler - runs on Node.js. Even when a site's core backend is written in another language, Node.js is usually involved in building and serving it. Companies like Netflix, PayPal and LinkedIn run parts of their platforms on Node.js.
Frequently asked questions
Node.js is a free, open-source runtime that lets JavaScript run outside the browser, directly on a server. It is most commonly used for backend APIs, real-time applications like chat and live notifications, and the build tooling behind modern frontend frameworks. It has existed since 2009 and is now stewarded by the OpenJS Foundation.



