A Brief Introduction to Deno

In this course, you will learn the basics of Deno and be able to get Deno up and running in absolutely no time.

What is Deno?

Deno, according to the official website, is a simple, modern, and secure runtime for JavaScript and TypeScript that uses V8 and is written in Rust.

Ryan Dahl, the original creator of Node.js announced Deno at JSConf EU 2018 in his talk, “10 Things I Regret About Node.js.” Deno is similar to Node; however, since it was created to be a better implementation of Node.js, Deno has many improvements. It has many useful features such as security by default, TypeScript by default, ES modules, and Golang-like package management.

Key features of Deno

  • Secure by default
  • No file, network, or environment access, unless explicitly enabled
  • Supports TypeScript out of the box
  • Ships only a single, executable file
  • Has built-in utilities such as a dependency inspector (Deno info) and a code formatter (Deno fmt)
  • Has a set of reviewed, or audited, standard modules that are guaranteed to work with Deno

Secure by default

This means that your Deno code does not have access to your system without your approval. Thus, it cannot write/read files, access your network ports, or even use plug-ins unless you allow it.


TypeScript has been around for quite some time. Typescript is a strongly typed superset of JavaScript, which is why a lot of developers prefer working with it. Deno has first-class TypeScript support, which means that we don’t have to compile Typescript separately. Deno takes care of that. Throughout this course, you will learn about TypeScript in greater detail and how it integrates with Deno.

ES modules

Deno fully embraces ES modules. It doesn’t use a package manager like npm but, instead, allows the user to import modules directly from their URLs, much like Golang.

Why should you learn Deno?

The world of web development is fast-paced. With the emergence of new technologies, it’s important to know which technology might become more widely used in the future. Deno, with its feature set, is predicted to be an integral part of web development in the near future.


While this course is meant to teach you the basics of backend web development with Deno, familiarity with JavaScript is essential. Also, it’s preferred that you learn about Node.js first because it has a larger community, and you’ll be able to understand why Deno was designed as an improvement to Node.js.

Will Deno replace Node.js?

No. Too many applications use Node.js in production. Node.js isn’t inferior. While Deno is meant to be an improvement, Node.js is, on its own, a great runtime. Thus, Deno will exist as a sibling to Node.js.