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Runtime Challenge: Bun vs Node.js

Explore the fundamental details of a new introduction that challenges the role of Node.js: Bun Runtime.

Tech Team


In the ever-changing world of JavaScript, we need to stay updated with its latest advancements. Today, we'll explore the fundamental details of a new introduction that challenges the role of Node.js: Bun Runtime. Get ready to find out what this innovation signifies for software engineers and the change it brings. 

What is Bun? 

In November 2023, Bun made its debut—a new JavaScript runtime constructed from the ground up. Designed to cater to the modern JavaScript ecosystem, Bun strives to enhance various aspects, including:

  • Speed: Bun starts and runs swiftly. It extends JavaScriptCore, the performance-oriented JS engine designed for Safari. This is crucial as computing transitions towards the edge.

  • Elegant APIs: Bun offers a minimal set of highly optimized APIs to accomplish common tasks such as launching an HTTP server and writing files.

  • Comprehensive Developer Experience (DX): Bun serves as a comprehensive toolkit for crafting JavaScript applications, incorporating a package manager, test runner, and bundler.

Does Bun Really Affect Node.js? 

Even on the Bun webpage, emphasis is placed on the fact that this runtime is purposefully designed as a drop-in substitute for Node.js. It inherently integrates numerous Node.js and Web APIs, encompassing [fs], [path], [Buffer], and others.

Bun aims to execute most of the world's server-side JavaScript while furnishing tools to enhance performance, simplify complexities, and amplify developer productivity. One of the reasons why Bun is considered faster than Node.js is because it uses the JavaScriptCore engine, while Node.js uses the JavaScript V8 engine. The former has been optimized for faster startup time.

Additionally, by supporting Node-style module resolution, Bun aims to achieve complete compatibility with the built-in Node.js globals (such as process, Buffer) and modules (like path, fs, http, etc.). This is an ongoing effort that remains incomplete. You can refer to the compatibility page on Bun for the current status.

Bun vs Node 

So, the creators of Bun have a clear intention to address the shortcomings present in Node.js. However, how ready is Bun for this challenge?

As it is stressed on the Dev.to webpage, a performance benchmark was conducted using an HTTP handler to render a server-side React page. It revealed that Bun manages around 68,000 requests per second. In comparison, Node.js handles approximately 29,000 and 14,000 requests per second. This highlights a significant difference in performance among them. Nevertheless, we should keep in mind that these tests are conducted under ideal conditions and therefore will never be the same in the real world and applications.

Yet, Bun has a smaller ecosystem compared to Node.js. The Node Package Manager (npm) boasts an extensive collection of packages and modules, providing a broad array of open-source options. As a new runtime, Bun must decide whether to construct additional functionalities from scratch or adapt existing Node modules to its new environment.

“Deno” as an Alternative?

Choosing between Bun and Node.js shouldn't be seen as the only option available. In 2018, Deno emerged as a Rust-based JavaScript runtime, aiming to improve upon Node.js features.

Deno is specifically designed to provide enhanced support for JSX and TypeScript, aligning more closely with web standards. Additionally, it simplifies deployment by packaging applications as self-contained executables.

In the aforementioned performance test, Deno demonstrated similar performance to Node.js, handling around 29,000 to 14,000 requests per second, which doesn't significantly outpace Bun’s speed.

However, Deno's major strength lies in its security. Operating within a secure sandbox environment, Deno requires explicit permission to access file systems, networks, and the environment, thus minimizing potential vulnerabilities.

Therefore, a simplified recommendation would be: for prioritizing security, Deno is an excellent choice; if speed is a priority, Bun might be more suitable.

Comparison of Node.js, Deno and Bun
Node, Deno, Bun

Final Thoughts

The choice of runtimes depends on your preferences and main focus. Choose wisely, but staying up to date with trends is crucial.

Our primary advice is to continuously learn and keep up with the latest developments. One way to achieve this is by following our blog, LinkedIn, and Instagram, where we cover many interesting topics. And, of course, feel free to reach out to us with any questions or queries. We're here to help!

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