Deno vs Node - a side by side comparison

With the increasing demand for high-performing web applications, server-side web development is also rapidly growing. Developers are constantly seeking new tools and technologies to create highly secure web applications with improved scalability. Two notable contenders in the realm of server-side JavaScript development are Deno and Node.js.

Traditionally, Node.js has been the go-to platform for server-side JavaScript development. However, with the introduction of Deno—a newer and more secure JavaScript runtime environment—many developers are considering whether it's time for a change.

In this blog, we'll guide you through Deno and compare it with Node.js in terms of performance, security, module management, and developer experience. We will delve into the pros and cons of each platform to help you choose the right back-end development service.

Understanding Deno and Node

Both Node.js and Deno are server-side JavaScript runtime environments that allow developers to execute JavaScript code outside the browser. However, there are several key differences between the two platforms. Launched in 2009, Node.js has become the leading platform for server-side JavaScript development. It uses the Chrome V8 JavaScript engine and follows an event-driven, non-blocking I/O model. This design allows for efficient and scalable handling of multiple connections, making it ideal for creating real-time applications that require high concurrency and low latency.

Deno, introduced in 2018 by Ryan Dahl, the creator of Node.js, aims to address some of the limitations seen in Node.js. It also uses the Chrome V8 JavaScript engine but offers a more secure default configuration and a decentralized module system. Additionally, Deno includes native support for TypeScript, a typed superset of JavaScript. Unlike Node.js, Deno does not use npm; instead, it allows developers to import modules directly from URLs or local files. This approach removes the need for a centralized module and package registry, which can be a potential failure point or security risk.

Deno vs Node - comparison:

Security

One of the main areas where Deno differs from Node.js is in its approach to security. Deno was built with security in mind from the start, therefore it has a more secure setup when we compare it to Node.js.

Approach difference between Deno and Node.js:

• Node.js permits you to have full access to the server's resources which also include the file system and network.
• Deno provides a more restrictive default configuration that limits a script's access to the server's resources.

Let’s take a look at this security approaches with an example:

In Node.js, a common way to read a file from the file system is to use the built-in fs module. Here's an example:

    

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const fs = require('fs');

fs.readFile('temp.txt', (error, datavalue) => {
  if (error) {
    console.error(error);
    return;
  }
  console.log(datavalue.toString());
});

This code reads the contents of a file named temp.txt and logs them to the console. There are no security checks in place - if this code was performed on a server with sensitive information, any attacker can easily use it to read the files, that too without any authorization.

In contrast, here's how you would read a file in Deno:

    

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const datavalue = await Deno.readFile('temp.txt');
console.log(new TextDecoder().decode(datavalue));

The code may be similar, but there are a few key differences. First, the fs module has been replaced with the built-in Deno object, which provides access to various Deno APIs. Second, instead of using a callback function, the code uses await to wait for the file to be read before continuing.

However, the most significant difference in Deno is that, the script must explicitly request access to the file system using a command-line flag:

    

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deno run --allow-read myscript.ts

This ensures that the script has only the necessary permissions and cannot access the file system without explicit authorization.

Node.js provides full access to the file system by default, while Deno requires scripts to explicitly request access. This makes Deno a more secure choice for applications where security is a top concern.

Memory usage

Efficient memory utilization is essential for server-side applications because it impacts both performance and scalability. Generally, Deno consumes less memory than Node.js for similar tasks, owing to its distinct architecture and runtime model. Here’s a more comprehensive comparison of the memory usage between Deno and Node.js.

When compared to Node.js, Deno's multi-threaded architecture and more efficient use of system resources can result in lower memory use and greater performance in some cases. If memory usage is a top concern for your application, Deno may be a better choice than Node.js.

Package mangement

Node.js uses the npm (Node Package Manager) ecosystem for package management. npm enables developers to simply install and manage packages, as well as to publish their own packages for usage by others.

Here's an example of how to install and use the popular axios package in Node.js:

    

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// index.js
const axios = require('axios');

axios.get('https://jsonplaceholder.typicode.com/todos/1')
  .then(response => console.log(response.data.heading)
  .catch(errors => console.error(errors));

In this example, we are using the axios package to make an HTTP request to an API and retrieve some data. We can then log the title property of the first todo to the console.

To install the axios package in Node.js, we can use the npm install command:

    

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npm install axios

This will install the axios package and all its dependencies in our project.

Deno, on the other hand, has a built-in package manager called deno. The deno command allows developers to easily install and manage packages, as well as specify permissions and import modules from remote URLs.

Here's an example of how to install and use the popular axios package in Deno:

    

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deno install --allow-net index.ts

This will install the axios package and all its dependencies in our project, and also specify the allow-net permission to allow the code to make HTTP requests.

Deno and Node.js both feature powerful package management systems, however Deno's built-in package manager may be more convenient in some situations. Node.js and Deno also differ because of the robust ecosystem provided by Node.js. It includes a variety of packages and tools for complex applications.

APIs

You can carry out various tasks such as file system operations, network communications, and HTTP handling with built-in APIs provided by Node.js. Here's an example of using Node.js's built-in http module to create a simple HTTP server:

    

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// server.js
const http = require('http');

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

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

In this example, we create an HTTP server to listen to port 3000. After a request is sent to the server, you will recieve a basic “Hello, World!” message in response.

Deno takes a more modular approach to APIs. Instead of built-in APIs, it offers a collection of small, modular modules that may be coupled to construct more complicated functionality.

Here's an example of using Deno's built-in http module to create a similar HTTP server:

    

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// server.ts
import { serve } from 'http';

const server = serve({ port: 3000 });

console.log('Server is on http://localhost:3000');

for await (const req of server) {
  req.respond({ body: 'Hello, World!\n' });
}

In this example, an HTTP server that listens on port 3000 is created using the serve function. You will receive a simple "Hello, World!" message from the server in response to a request.

As you can see, the design philosophy is primarily where Deno and Node.js vary in their APIs. The decision ultimately boils down to the needs of the project and the developer's tastes, as both systems have benefits and drawbacks.

Typescript support

Developers can write Node.js apps in TypeScript easily. However, Node.js TypeScript support is not as frictionless as Deno's, as developers must configure a separate compilation step to convert TypeScript code to JavaScript. Refer to this for using TypeScript in your application:

    

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// index.ts
function greet(name: string): string {
  return `Hello, ${name}!`;
}

console.log(greet('World'));

In this example, we define a simple greet function that takes a name argument and returns a greeting message. We then call the greet function with the argument 'World' and log the result to the console.

To run this code in Node.js, we need to compile it to JavaScript first using the tsc TypeScript compiler:

    

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$ tsc index.ts

This will create a index.js file that we can run with Node.js:

    

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$ node index.js
Hello, World!

Whereas, Deno provides seamless support for TypeScript out of the box. Deno can run TypeScript code directly without any additional compilation step. Here's an example of using TypeScript in a Deno application:

    

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// index.ts
function greet(name: string): string {
  return `Hello, ${name}!`;
}

console.log(greet('World'));

In this example, we define the same greet function as before and call it with the argument 'World', just like in the Node.js example.

To run this code in Deno, we simply execute the TypeScript file with the deno command:

    

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$ deno run index.ts
Hello, World!

Deno and Node.js both support TypeScript. The only difference is that in Deno we don't have the requirement for an extra compilation step but Node.js require an additional step to compile TypeScript code to JavaScript.

This makes Deno a more convenient option for TypeScript developers.

Module

The CommonJS module system, which is based on the require function and the module.exports object, is used to manage modules in Node.js. They are commonly deployed through a package management such as NPM and can be shared and reused across several Node.js applications.

Deno uses a modern ES modules system that is based on the import statement and the export keyword. Deno modules are fetched and cached from URLs.

While Deno supports ES modules by default, it can also load CommonJS modules using the import function, which maps to require in Node.js. This means that Deno can use Node.js modules with some modifications to the code. For example, the following code shows how to use a Node.js module in Deno:

    

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// index.ts
import * as fs from 'fs/promises';

async function readFile(path: string): Promise<string> {
  const datavalue = await fs.readFile(path);
  return datavalue.toString();
}

console.log(await readFile('nodemodule.txt'));

Here, we used the fs module to read a file and print its contents. To read a file and print its contents to the console, you can use the fs module. We import the fs module using the import statement, but we need to specify the .js extension and the .promises suffix to make it work in Deno.

Deno and Node.js use modules to organize code, they use different module systems and have different approaches to module management. Deno's support for ES modules by default and its ability to load Node.js modules make it a more flexible and modern choice for module management.

Promises

The core syntax and usage of promises in Deno and Node.js are comparable. The Promises/A+ specification, which offers a common interface for generating, chaining, and managing promises, is implemented by both Deno and Node.js.

In Deno and Node.js, a promise denotes a value that might not be accessible right now but will be resolved eventually. There are three possible states for a promise: pending, fulfilled, or rejected. Value is returned when a promise is fulfilled, and an error is raised when it is rejected.

Here is an illustration of how to use Promises in Node.js and Deno:

    

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// index.ts in Deno
const promiseVar = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('hello world');
  }, 1000);
});

promiseVar.then((result) => {
  console.log(result); // 'hello world' after 1 second
}).catch((error) => {
  console.error(error);
});

    

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// index.js in Node.js
const promiseVar = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('hello world');
  }, 1000);
});

promiseVar.then((result) => {
  console.log(result); // 'hello world' after 1 second
}).catch((error) => {
  console.error(error);
});

In this example, we have created a Promise that gets resolved after 1 second. You can the handle the fulfilment of the Promise using then method and its rejection using the catch method.

Difference between Node.js and Deno based on upon Promises is that Deno provides a global window object which has Promise constructor, whereas in Node.js you can get Promise constructor included in the global namespace by default.

Additionally, Deno provides a top-level await keyword that allows you to await a Promise without being inside an async function, which is not currently available in Node.js.

Promises in Deno and Node.js are similar in functionality and syntax, but Deno provides some additional features and flexibility, such as the global window object and top-level await keyword.

Browser compatibility

To ensure your code is portable and interoperable, it should be browser compatible. In general, Deno and Node.js have different levels of browser compatibility due to their different design philosophies and runtime models.

Node.js lacks built-in support for browser APIs or client-side JavaScript. In contrast, Deno is specifically designed to seamlessly handle both server-side and client-side JavaScript. It includes native support for browser APIs and module loading, simplifying the process of creating code that can be easily used in both server and browser settings.

Here's an example of how Deno can be used to run client-side JavaScript code:

    

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// index.ts
const response = await fetch("https://jsonplaceholder.typicode.com/todos/1");
const todo = await response.json();
console.log(todo.title);

In this example, we are using Deno's built-in fetch function to make an HTTP request to an API and retrieve some JSON data. We can then log the title property of the first todo to the console.

This code can be run using the deno run command:

    

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$ deno run index.ts
Hello, World!

This will run the code in a Deno environment, which supports both server-side and client-side JavaScript.

Based on browser compatibility for your application, Deno turns out to be a better option when compared with Node.js. The reason behind this is the built-in support for browsers APIs and client-side JavaScript provided by Deno. But in case, if you are building a server-side application and don’t want multiple browser environments support for your application then Node.js is a suitable choice.

Community

Over a year, Node.js remains the more widely adopted technology, but Deno is gaining popularity and momentum. The following chart from Google Trends shows the search interest over time for Deno and Node.js:

As you can see, Node.js has consistently been more popular than Deno in terms of search interest, but Deno is also managing to maintain its grip.

When we look at community trends, Node.js has a more established and mature community, backed with great resources and support.

However, Deno has the advantage of being a more modern and streamlined technology, with a focus on security and simplicity. As a result, Deno may attract developers who are looking for a more modern and cutting-edge technology.

Popularity

In terms of popularity, Node.js is still the more widely adopted technology as Stack Overflow Developer Survey suggest 49.9% of developers using it for back-end developemt. In contrast, only 3.5% of respondents reported using Deno regularly.

Released in 2018, Deno is relatively a new technology. It is in the process of shaping its ecosystem, community, and adoption. From the time of release, Deno has been getting attention in the developer community and its popularity is steadily increasing.

According to the State of JavaScript 2020 survey, Deno was the second most wanted technology among developers, with 46.4% of respondents expressing interest in using it. In comparison, Node.js was the seventh most wanted technology, with 34.6% of respondents expressing interest. Moreover, Deno is a newer and emerging technology that is gaining traction and interest from developers.

Deno vs Node performance

The speed and efficiency of Deno and Node.js are important factors to consider when choosing a platform. Deno is specifically designed with performance and security in mind, using a more recent version of the V8 JavaScript engine than Node.js. Additionally, the built-in TypeScript compiler in Deno can further improve the performance of TypeScript code.

In terms of benchmarks, Deno has shown to perform slightly better than Node.js in some cases. Several benchmarks in the TechEmpower Framework Benchmarks, including JSON serialization, single query tests, and multiple queries tests, showed Deno outperforming Node.js.

It’s essential to note that, there are various factors on which actual performance of our application depends. It can depend on specific use cases, hardware and implementation details.

Deno vs Node vs Bun

We now know, Deno and Node.js are both JavaScript runtimes that allow developers to write server-side JavaScript applications. Let’s learn about Bun.

Bun is a web framework that runs on top of Deno. It is lightweight and fast where more emphasis is given on its ease of use and simplicity. While Deno provides a basic set of modules and tools, Bun provides additional functionality and structure for building web applications. Developers can build web applications more quickly with its  features like middleware support, routing, and error handling. Bun provides an additional layer of functionality and structure that can make building web applications even easier.

Deno alternatives to popular Node projects

We all are pretty familiar with the Node.js libraries and frameworks out there. So, wouldn’t it be good to look at some alternatives to Deno. Let’s look at some popular Deno alternatives that might help you in your next project.

1. Drash is a web framework for Deno that is similar to Express.js for Node.js. It offers a minimalist and flexible approach to building web applications with Deno, including features like routing, middleware, and request handling.
2. Oak is another web framework for Deno that offers a similar feature set to Drash, but with a focus on simplicity and performance. It includes middleware, routing, and HTTP/2 support.
3. Denon is a Deno alternative to the popular nodemon utility for Node.js, which is used for automatically restarting a server when code changes are detected. Denon offers similar functionality, including support for TypeScript and configurable watch patterns.
4. ABC is a full-stack web framework for Deno that includes features like database integration, authentication, and caching. It includes support for TypeScript, middleware, and request handling.

These are just a few examples of Deno alternatives to popular Node.js projects. As Deno’s  popularity and adoption graph is rapidly increasing, it is clear that more and more libraries and frameworks will be developed to support it.

Deno vs Node - which one to choose?

Deno and Node.js are both exceptional tools for server-side JavaScript development. While While Node.js has been the industry standard for more than a decade, Deno is a newer option which is considered to be more secure and modern.

However, for most Node applications, Deno may not be a good fit yet, as it still faces challenges like npm module compatibility. Despite this, Deno's growing popularity, robust standard library, and first-class TypeScript support make it a viable option for side projects or smaller-scale utilities. As the development of Deno progresses, it will likely continue to impact and improve the JavaScript server ecosystem and  become more widely adopted in the future.

Till then, happy coding!