Deno vs. Node.js: The Showdown Nobody Asked For But Everyone Needed

Okay, so picture this: it’s 11 p.m., I’ve got a cup of coffee that’s somehow both cold and scalding (a skill I’ve mastered), and I’m spiraling down the rabbit hole of JavaScript runtimes. Yeah, I know, wild Friday night, right? But hey, when you're a software engineer, your idea of "fun" sometimes involves comparing Deno and Node.js while your cat judges you from across the room.

For a little backstory on this notion, I have been juggling with Node.js for years now. It's like those worn-out clothes in your wardrobe that you just can’t seem to get rid of because they are still in working (quality) condition. It's comfortable, yet at times, you think of getting similar ones that are trendy on the market — the revised and new variants, you know.

Back to the main subject, enter Deno, the modern rival that everyone’s been buzzing about. Accustomed to Node.js for years, it is only a natural instinct for me to explore the element deeply and check for myself if it is worthy of all the hype around it or if it has equal or even better runtime. So, shall we break it down to get a better hang of it?

First Impressions: Who Even Names These Things?

Back in the late 2000s, when technology was somewhat an infant, Node.js was present in the industry since 2009. Built on Chrome’s V8 engine, Node.js has been steadily helping us build scalable apps. You can understand it as that version of Javascript, which is highly dependable and preferred by everyone in the crowd.

On the latest note, Deno was launched back in 2018. And, yes, it was also developed by the same guy, Ryan Dahl, the original creator of popular Node.js. Plot twist, right? He came back, pointed out everything he thought he messed up with Node, and then went, “Hold my coffee. I’ll fix it.” Deno was born with security, simplicity, and modern features at its core. And if you’re wondering about the name… I honestly don’t know. But Deno is an anagram of Node, so there’s that.

Round 1: Security

Let’s talk security because if you’re anything like me, you’ve had at least one “Oh no, I accidentally exposed an API key” moment. (We don’t talk about that project anymore.)

Node.js leaves security up to the developer, which means you better know your way around .env files and permissions — or else. Deno, though? It is like one of those paranoid friends that we all have who persist in double-checking the locks. Anyhow, Deno, by default, works in a protected sandbox that does not permit your code access to the network, file system, or even the environment variables unless explicit permission is given.

Here’s an example:

Node.js

const fs = require('fs');
fs.writeFileSync('./hello.txt', 'Hello, World!');
console.log('File written successfully!');

Deno

const encoder = new TextEncoder();
await Deno.writeFile('hello.txt', encoder.encode('Hello, World!'));
console.log('File written successfully!');

But if you try running that Deno code without permissions, you’ll get a big ol’ error message:

PermissionDenied: Requires write access to "hello.txt".

Yep, Deno doesn’t mess around. You’ll need to explicitly pass flags like --allow-write when you run the script. Is it slightly annoying? Sure. But does it save you from accidentally unleashing chaos? Definitely.

Round 2: Performance

Now, I’m no speed freak, but when it comes to runtimes, performance matters. You want your app to respond faster than your friends when you ask, “Who’s up for pizza?”

Both Node.js and Deno use the V8 engine, so they’re fast. But Deno is written in Rust, which gives it a slight edge in terms of performance and reliability. Rust’s memory safety features and concurrency model make it a beast under the hood. That said, Node.js has been around longer, and its performance optimizations are battle-tested.

I ran some benchmarks because, well, nerd:

Basic HTTP Server in Node.js:

const http = require('http');

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

server.listen(3000, () => console.log('Node server running on port 3000'));

Basic HTTP Server in Deno:

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

const server = serve({ port: 3000 });
console.log("Deno server running on port 3000");

for await (const req of server) {
  req.respond({ body: "Hello from Deno!" });
}

Results? Deno was slightly faster in handling requests, but we’re talking milliseconds here. For most real-world applications, the difference won’t be game-changing—unless you’re trying to build the next Twitter (or X? Is that what we’re calling it now?).

Round 3: Developer Experience

Okay, this part hit me hard. If you’ve been using Node.js, you know npm is the lifeblood of your project. It’s how you install packages, manage dependencies, and occasionally yell at your screen when node_modules grows to 2 GB.

Deno said, “Nah, we don’t do npm here.” Instead, it uses a decentralized module system. You import modules directly via URLs, like this:

import * as _ from "https://deno.land/x/lodash/mod.ts";

console.log(_.chunk([1, 2, 3, 4], 2));

At first, I was like, “Wait, what?” But then I realized how cool it is. No more bloated node_modules folders! No more worrying about package version mismatches! Just clean, straightforward imports. Still, I’ll admit it: I missed the convenience of npm and the sheer variety of packages it offers. Old habits die hard.

A Quick Comparison

Here’s a quick side-by-side to show how Deno and Node.js differ in syntax and style:

Reading a File

Node.js:

const fs = require('fs');
const data = fs.readFileSync('./file.txt', 'utf8');
console.log(data);

Deno:

const data = await Deno.readTextFile('./file.txt');
console.log(data);

Making an HTTP Request

Node.js (Using axios):

const axios = require('axios');
const response = await axios.get('https://api.example.com/data');
console.log(response.data);

Deno (Built-In Fetch):

const response = await fetch('https://api.example.com/data');
const data = await response.json();
console.log(data);

So, What Should Be Your Pick?

Let’s take time to analyze more. So, assuming that you are neck-deep working on Node.js projects, consider your priority; there is no need to switch ships if all is running fine. Node.js is now mature and has a vast ecosystem, and it can get all the jobs done. However, if you want to start afresh or build something emphasizing security aspects, Deno is worthy of consideration. It’s like Node’s cooler, more modern cousin who listens to indie bands before they get famous.

For me? I will probably keep playing around with both. Node.js feels like home to me at this point, but Deno has that shiny, new-toy appeal to it. What’s more, I am actually drawn to the concept of writing code that guarantees more future-proof. 

With all that out of my mind, I now need to move and clean my monitor as it is currently occupied by about 90% screenshots of error pop-ups and random code snippets. Classic case, right?

Your Turn!

Have you tried Deno yet, or are you sticking with Node.js? Drop your thoughts below — I’m always up for a good tech debate (bonus points if it involves memes).