If you have worked with modern web development tools for any length of time, you have almost certainly used Node.js without necessarily thinking much about what it is. You might have run npm install, executed a build script, or followed a tutorial that told you to type a command into a terminal. All of that relies on Node.js. This article explains what Node.js actually is, where it came from, and how it changed the way developers use JavaScript.
JavaScript Before Node.js
JavaScript was originally designed to run inside a web browser. It had no ability to access the file system, handle network connections, or run on a server. If you wanted to build a web server, you used a different language entirely: PHP, Ruby, Python, or Java were the common choices.
The missing piece was a JavaScript engine fast enough and capable enough to run JavaScript outside the browser in a useful way.
The V8 Engine
In 2008, Google released the V8 JavaScript engine as part of the Chrome browser. V8 compiled JavaScript directly to machine code rather than interpreting it line by line, making it significantly faster than previous JavaScript engines. Crucially, V8 was open source, which meant it could be used outside of Chrome.
What is Node.js?
In 2009, Ryan Dahl combined Google’s V8 engine with an event loop and a low-level I/O API to create Node.js. The result was a JavaScript runtime environment that could execute JavaScript code outside of a web browser, on a server or a local machine.
Node.js brought together two things that had not previously been combined: the ease and familiarity of a scripting language with the ability to handle Unix-style network programming. For the first time, developers could use JavaScript to write server-side code, command-line tools, and scripts that interacted with the file system and network.
A year later, in January 2010, npm (Node Package Manager) was introduced as the package manager for the Node.js environment. npm provided a registry of open-source packages that developers could install and share, and it grew rapidly into the largest software registry in the world.
What is Node.js Used For?
Node.js is widely used for:
- Web servers and APIs — frameworks like Express, Fastify, and Hapi are built on Node.js and are used to build backend services and REST APIs.
- Command-line tools — many of the development tools you use daily, including npm scripts, Vite, ESLint, and Prettier, run on Node.js.
- Build tooling — the entire frontend build ecosystem (bundlers, transpilers, test runners) depends on Node.js.
- Real-time applications — Node.js handles concurrent connections efficiently, making it well suited to chat applications, live updates, and streaming.
If you have worked with a MEAN or MERN stack, Node.js is the runtime that makes the server-side JavaScript possible. It is worth noting that when you are first learning these stacks, it is easy to mix up commands and APIs that belong to Express (a framework that runs on Node.js) with those that are native to Node.js itself. Express handles routing and HTTP; Node.js is the environment that runs it all.
Node.js Alternatives
Node.js has dominated server-side JavaScript for over a decade, but a new generation of runtimes has emerged to address some of its limitations. As of 2026, three runtimes are worth knowing about.
Node.js
Still the default choice for most production applications. Node.js 24 LTS, released in late 2025, introduced native TypeScript execution and a more unified module system. Its ecosystem of over three million npm packages and its long track record make it the lowest-risk option for production workloads.
Deno
Deno was created by Ryan Dahl, the same developer who created Node.js, as a response to design decisions he regretted in Node. Deno runs TypeScript natively, enforces a security-first model where scripts have no access to the file system, network, or environment variables unless explicitly granted, and uses web-standard APIs rather than Node-specific ones. Deno 2.x resolved earlier npm compatibility issues and now supports the vast majority of npm packages, making it a more practical option than it once was.
Bun
Bun is a newer runtime focused on performance. Written in Zig and using the JavaScriptCore engine (the same engine used by Safari) rather than V8, Bun is significantly faster than Node.js for many workloads and includes a built-in bundler, test runner, and package manager. Bun 2.0, released in early 2026, reached full stability and covers over 95% of the Node.js API. In December 2025, Bun was acquired by Anthropic, providing financial backing that reduces the risk of the project being abandoned.
A useful way to think about the three: Node.js is the stability-first choice, Bun is the performance-first choice, and Deno is the security-first choice. For most developers starting a new project in 2026, Node.js remains the pragmatic default, with Bun worth considering where performance is a priority.