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Alex Spinov
Alex Spinov

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Bun Has a Free JavaScript Runtime — 4x Faster Than Node.js With Zero Config

#javascript #node #webdev #bunjs

Node.js Was Revolutionary. In 2009.

Node.js gave us JavaScript on the server. But 17 years later, we still need separate tools for everything: npm for packages, npx for running, jest for testing, webpack for bundling, dotenv for env files, nodemon for hot reload.

What if one tool did all of that?

Bun: Everything Node Needs, In One Binary

Bun is a JavaScript runtime, bundler, test runner, and package manager — all in a single binary. Written in Zig for maximum performance.

The Speed 

npm install (fresh): 45 seconds
bun install (fresh): 4 seconds
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That is not a typo. Bun installs packages 10x faster than npm.

node server.js startup: 150ms
bun server.js startup: 30ms
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5x faster startup. Your serverless functions will love this.

Drop-In Node.js Replacement 

# Before
node index.js
npm install express
npx create-react-app

# After
bun index.js
bun install express
bunx create-react-app
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Most Node.js code works with zero changes. Just swap node for bun.

Built-in Features (No Dependencies)

1. Native TypeScript

# No ts-node. No tsconfig. Just run it.
bun run app.ts
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2. Built-in Test Runner

import { test, expect } from 'bun:test'

test('2 + 2', () => {
  expect(2 + 2).toBe(4)
})
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bun test  # No jest, no vitest, no config
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3. Built-in .env Loading

# Bun reads .env automatically
# No require('dotenv').config()
console.log(process.env.DATABASE_URL) // Just works
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4. Built-in Bundler

bun build ./src/index.ts --outdir ./dist
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No webpack config. No vite config. One command.

5. Built-in SQLite

import { Database } from 'bun:sqlite'
const db = new Database('app.db')
db.run('CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)')
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SQLite driver built into the runtime. No npm packages needed.

What Still Needs Node.js

  • Production apps with specific Node.js APIs: Some edge cases in crypto, streams, or worker_threads
  • Enterprise environments: Where Node.js LTS support matters
  • AWS Lambda: Bun runtime not available on all cloud providers

For development, scripting, and new projects — Bun is strictly better.

Install Bun 

curl -fsSL https://bun.sh/install | bash
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One command. Under 30 seconds. Available on macOS, Linux, and WSL.

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