What is new in Node.js 21?

Node.js is the popular JavaScript runtime environment. It has undergone a significant update with its Node.js 21 release. The arrival of the Node.js 21 version includes updates to V8 JavaScript Engine to 11.8 stable fetch/web streams. This new version includes improved performance, better developer experience, and enhanced capabilities.

Our developers at the Node.js development company are introducing you to the new features of Node.js. That includes the latest updates, and exploring the fresh additions, optimizations, and functionalities that make Node.js 21 a noteworthy evolution in the world of JavaScript development.

What Is Node.JS?

Node.js is a JavaScript run-time environment. It is an open-source and cross-platform environment for coding. It can run on MacOS, Unix, Linux, and more Windows. It runs on the V8 JavaScript engine. If you are looking forward to hire Node.JS developer, understanding the basics and features of the new version is vital.

Node.js empowers developers to run JavaScript code outside web browsers. It enables server-side scripting for dynamic web page content and managing back-end services. Several professional developers leverage the power of Node.js for its event-driven architecture and non-blocking I/O operations. Node.js efficiently handles simultaneous connections, making it ideal for real-time applications. Building strong and innovative applications across various domains. You must know about the positive and negative aspects of Node.js before selecting it for your next project.

Confused about what to choose between Node.js and Golang_

Notable changes in the Node.js 21

Node.js 21 is now introduced as a stable release. It will supersede version 20 in the current release line. This new version of Node.js adds a built-in web socket client and enhances support for ES modules. You must be looking for the answer to what are the new features of Node.JS 21. Scroll down to learn the updates and new features in the new version.

  • Stable Fetch/Web Streams
  • Built-in web socket client
  • V8 upgraded to V11.8
  • Support for globs in the Node.js test runner
  • ESM flag to flip module defaults
  • NPM upgraded to v10.2.0
  • Module customization hook is removed
  • Use the flush option to fs.writeFile function

Let’s read about all the features in detail below.

    1. Stable fetch/Web Streams :
      Stable fetch is the recent update to Node.js. It contains changes for both the fetch module and web streams. They are marked as stable after the recent update.
      It is going to impact form data, web streams, headers, requests, responses, and fetch.image1The fetch API is now promoted to stable status after the release of Node.js 21. Now Node.js developers can use it on their applications.code


    1. Built-in web socket client :
      You can implement standard web APIs in this version as well. It is enabled through the flag: –experimental-websocket. It implements the existing web platform APIs like the Aforementioned fetch and web stream APIs, Web Crypto API, WhatWG URL parser, and more.code


    1. V8 upgraded to V11.8 :
      As the heading implies, v8 is upgraded to v11.8. It is part of chromium 118. The new engine brings high performance and new language features that include array grouping, web assembly extended const expressions, array buffer, prototype, and transfer. Michael Zasso contributed this feature in the Node.js 21 version.


    1. Support for globs in the Node.js test runner :
      In the latest update of Node.js test runner provides support for glob expressions when writing the parameters for the test. It indicates that now developers can use powerful glob patterns to run the test more effectively and easily. It allows you to run tests for all files with the test.js extension.


    1. ESM flag to flip module defaults :
      It allows you to flip the default module system used by Node.js. It is clearly defined as ES modules and common JS. Sting input in this version is provided via –eval or STDIN if the input type of unsatisfied. If there is no package.json, files end in .js or with no extension file present in the same folder or other folder in the system.We call extensionless files web assembly. If experimental-wasm-modules are passed, the file begins with the web assembly preamble. Developers can figure out when to interpret files as ES modules.


    1. NPM upgraded to v10.2.0 :
      Node.js 21 has introduced a new sbom command that allows you to generate a software bill of materials for the ongoing project. This new version includes NPM v10.2.0. Read about the changes in the recent NPM releases on GitHub.


    1. Module customization hook is removed :
      You will notice that the module customization hook has been removed. Now you have to use “register” to transfer data from the application thread to the customization hook.


    1. Use the flush option to fs.writeFile function :
      Many times data is not flushed to permanent storage. It allows subsequent read operations to find stale data. It includes a flush option to the fs.writefile family of functions.


Other updates on Node.js 21

Some other features and updates are also included in this version. They are as follows.

    1. The use of a global navigator object allows access to hardware concurrency information via the navigator. hardware concurrency.


    1. fs.writeFile () includes a flush option. It makes sure that data is flushed to disk when the write operation is finished. You can avoid the use of redundant data in your code by doing so.


Looking for the top Node.js developers for your next project_

Also read: Why Netflix uses Node.JS?

Should you use Node.js 21 for your next project?

For now, it is better not to use Node.js for production. It is possible, that it will only be supported for one year. Well, many other versions receive long-term support, but for now, nothing is certain.

Also read: Why select Node.js for your next web application?


So far, you have learned what new Node.js 21 has to offer Node.js developers. From language features, tooling, standard library additions, and performance optimization it maintains a robust position as a JavaScript environment. Creating a web application and cross-platform applications Node.js plays a crucial role. If you also have a great idea for software development, Technource can offer experienced developers at a reasonable cost.

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Mr. Sanjay Singh Rajpurohit, An early-aged entrepreneur who always leads his team from the front and achieved success. As the founder & CEO of Technource, a top mobile app & Web development company, he made a global presence in a short time by offering custom software development, premium mobile apps, and website development services to global clients. In his free time, he loves writing. He is featured on Hackernoon, Dzone, Enlear Academy, Articlesfactory, and much more websites.

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