Deno in 2 Minutes: Install, Hello World, and Core Features

Deno Overview

Deno v1.0.0 has been released. It is a V8‑based JavaScript and TypeScript runtime created by Ryan Dahl, the original creator of Node.js, who wanted to address design mistakes he perceived in Node.

Key Features

Secure by default: Deno cannot access the network or file system unless explicitly permitted.

Built‑in Promise support.

No npm; modules are imported via URLs or file paths, similar to browsers.

Native TypeScript support.

Installation

For macOS users, install via Homebrew: brew install deno For generic shell users, use the curl script:

curl -fsSL https://deno.land/x/install/install.sh | SH

Windows users can install with PowerShell:

iwr https://deno.land/x/install/install.ps1 -useb | iex

Additional installation methods are documented at https://github.com/denoland/deno_install .

Hello World Example

Save the following code as example.ts and run it with Deno:

import { serve } from "https://deno.land/[email protected]/http/server.ts";
const s = serve({ port: 8080 });
console.log("First deno example! Running on http://localhost:8080/");
for await (const req of s) {
  req.respond({ body: "Hello World
" });
}

Run the program: deno run example.ts If you encounter a permission error such as "PermissionDenied: network access to \"0.0.0.0:8000\"", re‑run with the appropriate flag: deno run --allow-net example.ts The console will then output:

First deno example! Running on http://localhost:8080/

Is Node.js Dead?

It is too early to say. While Deno offers a cleaner, more thoughtfully designed runtime, Node.js remains widely used in production, benefits from a large community, and is more mature.

For more information, visit https://deno.land/ .