Deno vs Node.js: Modern JavaScript Runtimes – Which One to Choose in 2021?

Namaste Developers! 👋

If you are a JavaScript developer like me, you must have heard about Deno – the new runtime that’s challenging Node.js. Many people are asking: “Is Deno better than Node.js? Should I switch?”

Don’t worry, today I’ll break this down in the simplest words. We’ll see what Deno is, how it compares to Node.js, and even write some code examples so you can decide for yourself.

1. What is Node.js?

Before we talk about Deno, let’s quickly recall what Node.js is. Node.js was created by Ryan Dahl in 2009. It allows us to run JavaScript outside the browser using the V8 engine. This opened the door to building fast, scalable backends with JavaScript.

Here’s a simple Node.js server example:

const http = require('http');

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello from Node.js Server!\n');
});

server.listen(3000, () => {
  console.log('Server running on http://localhost:3000');
});

Run it with:

node server.js

2. What is Deno?

Deno (created by Ryan Dahl in 2018) is like Node.js’s younger brother but with a modern twist. It’s built on the same V8 engine but written in Rust, not C++.

The most important difference? Deno is secure by default. This means it doesn’t allow file, network, or environment access unless you explicitly give permission.

Here’s the same server example in Deno:

import { serve } from "https://deno.land/std@0.90.0/http/server.ts";

const handler = (req) => new Response("Hello from Deno Server!");
serve(handler, { port: 3000 });

console.log("Server running on http://localhost:3000");

Run it with:

deno run --allow-net server.ts

Notice the --allow-net flag? Without it, Deno won’t allow network access. This is a big improvement over Node.js security.

3. Key Differences Between Deno and Node.js

Here’s a quick comparison table for you:

4. Why Use Deno?

Deno has many modern features, like:

1. Built-in TypeScript support – No need for tsconfig.json.
2. Security first – No accidental file or network access.
3. No node_modules folder – Import directly via URLs.

For example, here’s how you can import an external library in Deno:

import { bold, green } from "https://deno.land/std@0.90.0/fmt/colors.ts";

console.log(bold(green("Hello from Deno!")));

No need for npm install – simple and clean!

5. Should You Switch to Deno?

• If you’re building secure applications or love TypeScript, Deno is worth a try.
• But remember, Node.js has a huge ecosystem with tools like Express, React, and more.

For now, Node.js is still the king. But Deno is catching up fast, and as developers, we must keep learning.

Final Words 🌟

In 2021, Deno is exciting, but Node.js is still widely used. If you’re working on a new project, give Deno a try. It’s simple, secure, and built for the modern web.

Happy coding! 🚀