DEV Community

Alex Spinov
Alex Spinov

Posted on

Bun Has a Free JavaScript Runtime That's 4x Faster Than Node — Bundler, Test Runner, and Package Manager Built In

#bunjs #javascript #node #webdev

The Node.js Toolchain Problem

A Node.js project needs: Node runtime, npm/yarn/pnpm (package manager), esbuild/webpack (bundler), jest/vitest (test runner), tsx/ts-node (TypeScript runner). That's 5+ tools.

Bun replaces all of them. One binary. Written in Zig. 4x faster than Node.

What Bun Gives You

Fast Package Install 

bun install  # 25x faster than npm install
Enter fullscreen mode Exit fullscreen mode

Bun uses a global cache and hardlinks. node_modules appears in milliseconds.

Native TypeScript 

bun run server.ts  # No compilation step
Enter fullscreen mode Exit fullscreen mode

Built-In Bundler 

bun build ./src/index.ts --outdir ./dist
Enter fullscreen mode Exit fullscreen mode

Faster than esbuild. Supports code splitting, tree shaking, and minification.

Built-In Test Runner 

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

test('2 + 2', () => {
  expect(2 + 2).toBe(4);
});
Enter fullscreen mode Exit fullscreen mode 
bun test  # Jest-compatible API
Enter fullscreen mode Exit fullscreen mode

SQLite Built In 

import { Database } from 'bun:sqlite';

const db = new Database('app.db');
db.run('CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT)');
const users = db.query('SELECT * FROM users').all();
Enter fullscreen mode Exit fullscreen mode

Fetch API + WebSocket Server 

Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response('Hello from Bun!');
  },
  websocket: {
    message(ws, message) {
      ws.send(`Echo: ${message}`);
    },
  },
});
Enter fullscreen mode Exit fullscreen mode

Node.js Compatibility

Most npm packages work unchanged. Express, Fastify, Prisma, Next.js — all compatible.

Performance

Benchmark Node.js Bun
HTTP requests/sec 80K 300K
Package install 30s 1.2s
TypeScript startup 800ms 50ms
SQLite queries/sec N/A 1M+

Quick Start 

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

Why This Matters

JavaScript tooling shouldn't be slower than the code it runs. Bun proves that a runtime, bundler, test runner, and package manager can all be one fast tool.

Building fast APIs with Bun? Check out my web scraping actors on Apify Store — structured data at Bun speed. For custom solutions, email spinov001@gmail.com.

Top comments (0)