DEV Community

Alex Spinov
Alex Spinov

Posted on

Bun Has a Free JavaScript Runtime That's 3x Faster Than Node.js

#javascript #node #bunjs #performance

Node.js uses V8. Deno uses V8. Bun uses JavaScriptCore (Safari's engine) — and it's significantly faster for everything: startup, HTTP serving, file I/O, package installation, and testing.

Here's why Bun is production-ready in 2026.

What Bun Gives You for Free

  • JavaScript runtime — 3x faster startup than Node.js
  • Package manager — bun install is 25x faster than npm
  • Bundler — built-in, faster than esbuild for most cases
  • Test runner — bun test with Jest-compatible API
  • TypeScript/JSX native — no transpilation step needed
  • Node.js compatible — most npm packages work out of the box

Quick Start 

curl -fsSL https://bun.sh/install | bash
bun init
bun run index.ts  # TypeScript works natively
Enter fullscreen mode Exit fullscreen mode

HTTP Server (Built-in, Blazing Fast) 

// server.ts — no dependencies needed
Bun.serve({
  port: 3000,
  fetch(req) {
    const url = new URL(req.url);

    if (url.pathname === '/api/users') {
      return Response.json([
        { id: 1, name: 'Alice' },
        { id: 2, name: 'Bob' }
      ]);
    }

    return new Response('Not Found', { status: 404 });
  }
});

console.log('Server running on port 3000');
Enter fullscreen mode Exit fullscreen mode

Run with bun server.ts. No Express, no Fastify — the built-in server handles 100K+ requests/second.

Package Manager (25x Faster Than npm) 

# Install all dependencies
bun install          # ~500ms vs npm's ~12s

# Add a package
bun add express      # ~200ms

# Remove
bun remove express

# Run scripts
bun run dev          # Reads package.json scripts
Enter fullscreen mode Exit fullscreen mode

Bun uses a global cache and hardlinks, so repeated installs are nearly instant.

File I/O (The Killer Feature for Data Processing) 

// Read file — 10x faster than fs.readFile
const content = await Bun.file('data.json').text();
const data = await Bun.file('data.json').json();

// Write file
await Bun.write('output.txt', 'Hello, Bun!');
await Bun.write('data.json', JSON.stringify(data));

// Stream large files
const file = Bun.file('large.csv');
const stream = file.stream();
Enter fullscreen mode Exit fullscreen mode

SQLite Built-In 

import { Database } from 'bun:sqlite';

const db = new Database('myapp.sqlite');

db.run(`CREATE TABLE IF NOT EXISTS users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  name TEXT NOT NULL,
  email TEXT UNIQUE
)`);

const insert = db.prepare('INSERT INTO users (name, email) VALUES (?, ?)');
insert.run('Alice', 'alice@example.com');

const users = db.query('SELECT * FROM users').all();
console.log(users);
Enter fullscreen mode Exit fullscreen mode

No better-sqlite3 or sql.js needed. SQLite is built into Bun.

Test Runner (Jest-Compatible) 

// math.test.ts
import { describe, it, expect } from 'bun:test';
import { add } from './math';

describe('add', () => {
  it('adds two numbers', () => {
    expect(add(1, 2)).toBe(3);
  });

  it('handles negatives', () => {
    expect(add(-1, 1)).toBe(0);
  });
});
Enter fullscreen mode Exit fullscreen mode 
bun test              # Runs all *.test.ts files
bun test --watch      # Watch mode
bun test --coverage   # Code coverage
Enter fullscreen mode Exit fullscreen mode

Benchmarks (Real Numbers)

Operation Bun Node.js Deno
Startup time 7ms 25ms 20ms
HTTP req/sec 120K 45K 50K
install (cold) 0.5s 12s N/A
File read (1GB) 1.2s 3.8s 3.1s
SQLite ops/sec 50K 30K* N/A
Test suite (100) 0.3s 2.1s 1.5s

*Node.js requires better-sqlite3 package

Node.js Compatibility

Bun implements most Node.js APIs:

  • fs, path, os, crypto, http, https ✅
  • child_process, worker_threads ✅
  • Express, Fastify, Koa, Hono ✅
  • Most npm packages work unchanged ✅

Who's Using Bun

  • Oven (company behind Bun) uses it in production
  • Growing adoption in startups prioritizing performance
  • 75K+ GitHub stars — one of the fastest-growing JS projects

The Verdict

Bun isn't just a faster Node.js — it's a complete JavaScript toolkit. Runtime + package manager + bundler + test runner in one binary. If you're starting a new project, Bun gives you everything Node.js does, faster.

Need help building production web scrapers or data pipelines? I build custom solutions for startups and enterprises. Reach out: spinov001@gmail.com

Check out my awesome-web-scraping collection — 400+ tools for extracting web data.

Top comments (0)