JavaScript Runtimes Compared: Evaluating Bun, Deno, and Node

Deno vs Bun vs Node

The JavaScript landscape is constantly evolving, with new runtimes emerging to challenge the established dominance of Node.js. Two such contenders are Bun and Deno, both vying for developer attention with promises of enhanced performance and improved security. But what is the difference between Deno vs. Bun vs. Node?

This comprehensive guide delves into the key features and functionalities of Bun vs Deno vs Node, enabling developers to make informed decisions when choosing the  Node.js vs. Deno vs. Bun runtime for their next project.

What is Deno vs. Bun vs. Node?

JavaScript runtimes are environments in which JavaScript code can be executed. They provide the necessary infrastructure for interpreting and running JavaScript code. There are many different runtimes to choose from, so you have to weigh up Deno vs. Node vs. Bun performance against your needs before making a decision. 


Node.js, released in 2009, has become the de facto standard for server-side JavaScript development. Its core strengths include:

Vast Ecosystem: Node.js boasts an extensive ecosystem of libraries, frameworks, and tools, catering to virtually every development need. Popular choices include Express.js for building web applications, React for user interfaces, and Mongoose for interacting with databases.

Mature and Stable: With over a decade of active development, Node.js is a mature and stable platform. This translates to robust performance, a wealth of documentation and community support, and a lower risk of encountering unexpected bugs.

Large Developer Community: Node.js has a massive developer community, making it easier to find solutions, troubleshoot issues, and access learning resources.

Node.js also has limitations:

  • Security Concerns: Node.js relies on a permissive module system, which can potentially introduce security vulnerabilities if developers aren’t cautious about the packages they install.
  • Performance Bottlenecks: While generally performant, Node.js can struggle with CPU-intensive tasks due to its single-threaded nature.
  • Module Bundling Complexity: For complex applications, managing dependencies and building production-ready bundles can be a cumbersome process.


Deno, launched in 2018, offers a fresh take on JavaScript runtime environments. Its core features include:

Built-in Security: Deno prioritizes security by adopting a permission-based system. Modules have explicit permission declarations, reducing the risk of code injection or unauthorized access.

TypeScript by Default: Deno natively supports TypeScript, a superset of JavaScript that enables static typing and improves code quality and maintainability.

Bundler Integration: Deno integrates a bundler by default, simplifying the process of building production-ready applications without the need for external tools.

There are downsides, too: 

  • Limited Ecosystem: While Deno’s ecosystem is rapidly growing, it still lags behind Node.js in terms of the sheer volume and maturity of available libraries and frameworks.
  • Newer and Less Stable: As a relatively new platform, Deno might have fewer battle-tested solutions than Node.js, potentially leading to encountering unforeseen challenges.


Bun, the newest entrant in the ring, has garnered significant attention for its focus on raw performance. Here’s what sets it apart:

Blazing-Fast Speed: Bun leverages the JavaScriptCore engine from WebKit, which is known for its exceptional speed. Benchmarks suggest Bun can outperform both Node.js and Deno in terms of startup times, request handling, and overall performance.

Zero-Cost Abstraction Layer (ZAL): Bun employs a ZAL, written in Zig, a low-level systems programming language. This provides fine-grained control over memory management and contributes to Bun’s speed advantage.

Integrated Tools: Similar to Deno, Bun includes a built-in bundler, testing tools, and a development server, streamlining the development workflow.

Again, there is a downside:

  • Immature Ecosystem: As the newest player, Bun’s ecosystem of libraries and frameworks is still in its nascent stages. Developers might face challenges finding specific tools or encountering compatibility issues with existing projects.
  • Rapid Development Pace: Bun’s rapid development can lead to frequent breaking changes, potentially requiring more frequent code adjustments to maintain compatibility with the latest updates.

Choosing Node vs. Deno vs. Bun

While benchmarks and performance claims are abundant, it’s crucial to consider your specific project requirements when evaluating  Deno vs. Node vs. Bun performance. Here’s a breakdown of key considerations:

Application Type: Bun’s superior performance might be a major advantage for CPU-bound tasks. However, for I/O-bound tasks, the difference between the runtimes might be less significant.

Project Complexity: If your project relies heavily on existing libraries and frameworks, Node.js’ mature ecosystem might outweigh Bun’s speed advantage.

Security Priorities: For security-sensitive applications, Deno’s built-in security features might be a deciding factor.

Development Workflow: Consider the development tools and workflows you’re accustomed to. Bun and Deno’s integrated features might streamline your process, while Node.js might require additional tools for similar functionalities.

Choosing the Right Runtime For Your Project

The optimal choice between Node.js, Deno, and Bun hinges on a confluence of factors specific to your project:

  • Project Requirements: Evaluate your project’s needs for performance, security, existing library compatibility, and development workflow preferences.
  • Team Expertise: Consider your team’s familiarity with each runtime and their comfort level in potentially adopting a newer technology like Bun.
  • Future-Proofing: While Node.js is established, Deno and Bun’s focus on modern features and security best practices might be a better fit if long-term sustainability is a priority.
  • Evolving JavaScript Standards: The JavaScript language and its ecosystem are constantly evolving. All three runtimes are likely to adapt and integrate new features as they emerge.
  • The Rise of WebAssembly (WASM): WASM allows compiling code written in various languages (like C++) to run in web browsers. This could potentially impact the way developers build high-performance applications in the future, potentially affecting all three runtimes.
  • Focus on Developer Experience: The developer experience, encompassing tools, workflows, and ease of use, will continue to be a major factor in developers’ choice of runtime.
Deno vs Bun vs Node


The emergence of Bun and Deno, alongside the established presence of Node.js, presents developers with a wider range of options for building JavaScript applications.  Understanding the strengths and weaknesses of each runtime empowers informed decision-making, allowing developers to choose the Deno vs. Bun vs. Node option that best aligns with their specific project needs and development preferences.  Ultimately, this healthy competition fosters innovation and a more robust JavaScript ecosystem, benefiting developers and users alike.

Author: Michael K. Wallace

Michael is an experienced IT professional with over a decade of software development, project management, and business analysis expertise. He has a passion for leveraging technology to drive business growth and innovation. Michael enjoys sharing his insights and knowledge through writing and is dedicated to helping businesses succeed in the ever-evolving IT landscape.