Bun vs Node.js: Is It Worth Switching in 2026?

Bun promises 3x faster startup, built-in TypeScript, and a batteries-included runtime. After a year of production use, here's the honest comparison.

What Bun Is

Bun is a JavaScript runtime (like Node.js), bundler (like Webpack/esbuild), test runner (like Jest), and package manager (like npm) — all in one binary.

Performance

# Startup time
node index.js   # ~80ms
bun index.ts    # ~6ms

# Install dependencies
npm install     # ~15s (fresh)
bun install     # ~1.5s (fresh, ~10s with frozen lockfile)

# HTTP server throughput (req/sec)
Node.js: ~85,000
Bun:     ~160,000

TypeScript Without Config

// No tsconfig needed, no ts-node, no compilation step
// Just run it:
// bun index.ts

const greet = (name: string): string => `Hello, ${name}`;
console.log(greet('Atlas'));

Built-in APIs

// File read — faster than Node.js fs
const file = Bun.file('./data.json');
const data = await file.json();

// HTTP server — no Express needed for simple cases
Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response('Hello World');
  },
});

// SQLite — built in, no install
import { Database } from 'bun:sqlite';
const db = new Database('app.db');
const users = db.query('SELECT * FROM users').all();

// Password hashing — built in
const hash = await Bun.password.hash('mypassword');
const valid = await Bun.password.verify('mypassword', hash);

Drop-In Node.js Replacement

# Most Node.js code runs without changes
bun run server.js

# Replace npm scripts
bun run dev
bun test
bun build ./src/index.ts --outdir ./dist

Where Bun Wins

• Scripts and CLI tools (fast startup)
• TypeScript projects (zero config)
• API servers (higher throughput)
• Monorepos (bun workspaces + fast install)

Where Node.js Still Wins

• Production deployments (more battle-tested)
• Packages with native bindings (some fail with Bun)
• Enterprise environments (IT policies)
• When Next.js is your framework (Next requires Node.js)

Verdict

Use Bun for: scripts, CLI tools, API servers, new projects.

Keep Node.js for: Next.js apps, projects with complex native deps, production when stability > speed.

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