Bun — All-in-One JavaScript Runtime & Toolkit

What Bun Replaces

Runtime Performance

# HTTP server benchmark (requests/second)
Bun:     145,000 req/s
Node.js:  36,000 req/s
Deno:     67,000 req/s

Native TypeScript

Run .ts files directly — no tsconfig.json, no build step:

bun run server.ts  # Just works

Package Manager Speed

# Installing a fresh Next.js project
npm install:  45 seconds
bun install:   1.8 seconds  (25x faster)

Built-in Test Runner

// math.test.ts
import { expect, test } from "bun:test";

test("addition", () => {
  expect(2 + 2).toBe(4);
});

bun test  # Runs all .test.ts files

Built-in Bundler

bun build ./src/index.ts --outdir ./dist --minify

Node.js Compatibility

Bun implements most Node.js APIs:

• fs, path, http, crypto, stream
• process.env, __dirname, require()
• npm packages work as-is

Bun-Specific APIs

// Fast file I/O
const file = Bun.file("data.json");
const data = await file.json();

// Built-in SQLite
import { Database } from "bun:sqlite";
const db = new Database("mydb.sqlite");

// Fast HTTP server
Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response("Hello from Bun!");
  },
});

Key Stats

• 78,000+ GitHub stars
• 4x faster than Node.js
• 25x faster package install
• Native TypeScript support
• Drop-in Node.js compatible

FAQ

Q: What is Bun? A: Bun is an all-in-one JavaScript runtime, package manager, bundler, and test runner that is 4x faster than Node.js and drop-in compatible with most Node.js code.

Q: Is Bun free? A: Yes, fully open-source under MIT license.

Q: Can I use Bun in production? A: Yes, Bun 1.0+ is production-ready. Companies like Figma and Sentry use it.