Deno vs Node: the next evolution of JavaScript, but are we ready for it?

There’s no doubt about that Node.js is the most popular and widely used JavaScript runtime environment today. However, with the release of Deno in 2018, the development community was introduced to a new, more secure and modern alternative to Node.js. Deno was created by the same developer, Ryan Dahl, and was designed to address several shortcomings in Node.js. The big question is: can Deno replace Node.js as the default JavaScript runtime? Despite the excitement surrounding the introduction of Deno, its adoption has been slow and Node.js remains dominant.

In this article, we will explore why developers continue to prefer Node.js over Deno despite Deno’s modern design and security features. We will also compare the two platforms in several critical areas.

What is Node.js?

• Node.js is an open-source, cross-platform, server-side JavaScript runtime environment built on Google’s V8 JavaScript engine. Released in 2009, Node.js revolutionized web development by enabling the use of JavaScript on the server side.
• Node.js uses a single-threaded, non-blocking, event-driven architecture, making it ideal for building scalable, data-intensive, real-time applications that run on distributed devices. Its power lies in the ability to handle thousands of connections simultaneously with minimal memory usage, using callback functions for non-blocking I/O operations.
• Node.js has grown into a robust ecosystem supported by npm, a comprehensive package manager that allows developers to easily share and reuse code. This ecosystem is one of the key factors in Node’s continued popularity.

What is Deno?

Deno is a modern runtime for JavaScript, TypeScript, and WebAssembly, designed by Ryan Dahl in 2018 to address some design flaws he identified in Node.js. These include:

1. A poorly designed module system that relies on centralized distribution (npm).
2. Unstable legacy APIs.
3. A lack of security checks.

Deno aims to solve these issues by providing a more secure and developer-friendly experience. It was built with the following goals in mind:

• Security: Deno runs scripts in a sandbox environment, meaning they have no access to the file system, network, or environment unless explicitly granted.
• TypeScript support: Deno has built-in TypeScript support, allowing developers to write TypeScript without any additional configuration.
• Modern API: Deno uses modern web platform standards and uses features such as to retrieve And Web workers that are consistent with browser APIs.
• Single executable file: Deno is distributed as a single binary file, making it easy to install and use.

Deno vs Node.js: Key Differences

1. Module management

• Node.js: Node relies on npm (Node Package Manager) for third-party modules, and the dependency management system is centered around package.json and the node_modules folder. This centralized ecosystem has led to the creation of millions of modules that can be easily reused by developers.
• Deno: Deno, on the other hand, does not have a centralized package manager like npm. Instead, developers can import modules directly from URLs, such as GitHub or a CDN:

import { serve } from "https://deno.land/[email protected]/http/server.ts";

While this is more flexible, it also poses potential security risks if third-party URLs are compromised. However, Deno mitigates this with caching mechanisms that prevent redownloads unless necessary.

2. Security

One of the key features that differentiate Deno from Node.js is its default secure design.

• Node.js: In Node, scripts have full access to the file system, network, and environment variables by default. This openness can lead to vulnerabilities if not handled carefully, as third-party libraries can introduce malicious behavior.
• Deno: Deno enforces strict security controls and only grants permissions when explicitly allowed via command line flags. For example, to have Deno read the file system:

deno run --allow-read app.ts

You can grant fine-grained permissions for file access, network requests, and environment variables, making Deno a more secure environment by default.

3. TypeScript support

• Node.js: Although Node does not have native TypeScript support, developers can install the TypeScript package and configure it manually:

npm install -g typescript
tsc --init

Developers must transpile TypeScript to JavaScript before running it in Node.js, which can slow down development workflows.

• Deno: Deno has built-in TypeScript support, allowing you to run TypeScript files directly without any configuration:

deno run app.ts

This makes Deno an attractive option for developers who prefer TypeScript, as it eliminates extra settings and reduces friction.

4. APIs and callbacks

• Node.js: Node’s early APIs were based on callback functions, which often resulted in callback hell. While the introduction of Promises and asynchronous/wait in JavaScript has improved the situation, many older Node APIs still rely on callbacks.

fs.readFile('file.txt', (err, data) => {
  if (err) throw err;
  console.log(data);
});

• Deno: Deno is designed with modern JavaScript features in mind and supports async/await out-of-the-box. Deno’s APIs are promise-based by default, eliminating the need for callback-based patterns:

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

5. Performance

Both Deno And Node.js are built on Google’s V8 JavaScript engineso their performance characteristics are quite similar. However, Deno has a smaller memory footprint due to its more modern design.

• Node.js: Node.js is optimized for efficiently handling asynchronous I/O tasks. It excels at serving many concurrent connections with minimal memory overhead.
• Deno: Deno’s modern architecture and reliance on Rust and Tokyo for asynchronous tasks make it highly performant, although large-scale benchmarks between Node.js and Deno are still in development.

Why developers stick with Node.js
Despite Deno’s improvements over Node.js, the transition to Deno has been slow. The reasons are largely practical:

• Mature ecosystem: Node.js has been around since 2009 and has built a huge community and ecosystem of libraries, packages and tooling. Developers have years of experience with Node.js and the learning curve to move to Deno is a significant barrier.
• npm: The Node Package Manager (npm) is a huge repository of reusable code, making it easy to find libraries and packages for almost any functionality. Deno’s module system, while innovative, lacks the centralized management and community adoption of npm.
• Backwards compatibility: Many production systems rely on Node.js these days. Migrating to Deno would require rewriting or restructuring significant portions of the code, which may not justify the effort for most companies.
• Familiarity: Developers are familiar with the workflow, tools, and deployment processes in Node.js. Moving to a new maturity like Deno introduces uncertainty and risk, which many teams are reluctant to embrace.

Conclusion

Deno undoubtedly offers a modern, secure, and developer-friendly environment, but Node.js continues to dominate due to its mature ecosystem, extensive library support, and widespread adoption. While Deno addresses some key issues with Node, such as security and modularity, it is still an evolving platform.

For developers who need stability, a large community, and a wealth of third-party libraries, Node.js remains the preferred choice. However, as Deno matures and gains traction, it could become a viable alternative, especially for projects that prioritize security and TypeScript support by default.

Ultimately, the choice between Deno and Node.js depends on the specific needs of your project. If you’re building a greenfield project with an emphasis on security and modern JavaScript features, Deno is worth considering. For older applications or projects that rely on a large ecosystem of modules, Node.js still rules.

Thanks for reading!