Node.js vs Deno vs Bun: JavaScript Runtimes Compared

Node.js is the established runtime with the largest ecosystem, Deno offers modern defaults with TypeScript natively, and Bun focuses on raw speed — three JavaScript runtimes with different philosophies.

At a Glance

Key Differences

• Runtime philosophy: Node.js follows a pragmatic approach with npm and CommonJS/ESM hybrid. Deno prioritizes web standards — it uses ES modules, URL imports, browser-compatible APIs, and explicit permissions. Bun aims for Node.js compatibility with dramatically better performance using JavaScriptCore instead of V8.
• TypeScript support: Deno runs TypeScript natively without any configuration — just deno run file.ts. Bun also supports TypeScript natively using its built-in transpiler. Node.js requires third-party tools like ts-node, tsx, or a build step with tsc. In 2026, Node.js 22+ has experimental TypeScript stripping via flags.
• Performance: Bun is consistently 2-4x faster than Node.js for HTTP servers and script startup. Its JavaScriptCore engine and native runtime (written in Zig) give it the edge. Deno sits between Node.js and Bun in benchmarks. For CPU-bound tasks, V8 (Node/Deno) and JavaScriptCore (Bun) are comparable.
• Package management: npm (Node) has the largest registry by far — over 2 million packages. Deno can import from deno.land/x, npm (via npm: specifier), or directly from URLs. Bun ships its own package manager (bun install) that’s 10-30x faster than npm install.
• Security: Deno is the most secure by default — scripts have no file, network, or environment access unless explicitly granted via --allow-read, --allow-net, etc. Node.js and Bun give scripts full system access by default, which is convenient but less secure.

When to Choose Node.js

Node.js is the safe bet — it powers the vast majority of production JavaScript backends. npm has every package you’ll ever need. Express, Fastify, Prisma, Socket.io, and most frameworks are built for Node.js. The job market is enormous. Serverless platforms (AWS Lambda, Vercel, Netlify) have first-class Node.js support. If you’re building anything in production today, Node.js is the most mature and well-supported choice.

Use Node.js for: production APIs (Express/Fastify), enterprise backends, serverless functions, npm-published libraries, and teams that value ecosystem stability over performance.

When to Choose Deno or Bun

Deno is ideal for new projects where you want modern defaults: TypeScript without config, web-standard APIs (fetch, Request, Response), and secure-by-default permissions. Its fresh module system avoids the complexity of node_modules. Bun is for performance-critical workflows — it starts scripts in milliseconds and runs HTTP servers at speeds rivaling Go and Rust. Bun’s built-in test runner, bundler, and package manager reduce dev toolchain complexity.

Use Deno for: new TypeScript-first projects, CLI tools, scripts that benefit from permission sandboxing, and teams embracing web standards. Use Bun for: fast CI/CD pipelines, serverless functions where cold start matters, monorepo scripts, and high-throughput HTTP services.

Side by Side Code Example: HTTP Server

Node.js

import { createServer } from "node:http";

const server = createServer((req, res) => {
  res.writeHead(200, { "Content-Type": "text/plain" });
  res.end("Hello from Node.js");
});

server.listen(3000, () => {
  console.log("Node.js running on http://localhost:3000");
});

node server.js

Deno

// No imports needed — uses Web Standards API
Deno.serve((req: Request) => {
  return new Response("Hello from Deno", {
    headers: { "Content-Type": "text/plain" },
  });
});

// Or use the standard fetch API:
// Deno.serve({ port: 3000 }, handler)

deno run --allow-net server.ts

Bun

Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response("Hello from Bun", {
      headers: { "Content-Type": "text/plain" },
    });
  },
});

bun run server.js

Deno and Bun use web-standard Request/Response objects. Node.js uses its own IncomingMessage/ServerResponse API (though node:http now also supports web standards in recent versions). Bun’s Bun.serve is the fastest — handling 2-3x more requests per second than Node.js.

Expected Output (All Three)

# Visit http://localhost:3000 →
Hello from Node.js  # or "Hello from Deno", "Hello from Bun"

FAQ

Related Comparisons

Express vs Fastify — TypeScript vs JavaScript — pnpm vs npm vs Yarn — Webpack vs Vite