Deno vs Bun vs Node.js: Performance & Benchmarks

Yogesh Rathod — Thu, 06 Mar 2025 18:06:19 +0000

1. Introduction

Performance is a critical factor when choosing a JavaScript runtime. This document compares Deno, Bun, and Node.js based on execution speed, startup time, HTTP request handling, and other key benchmarks.

2. Performance Comparison

2.1 Startup Time

Bun has the fastest startup time due to its optimized JavaScript engine.
Deno is faster than Node.js, thanks to Rust's efficient memory management.
Node.js has slower startup times due to legacy design choices.

2.2 HTTP Server Performance

To test real-world performance, I implemented a custom HTTP application server that generates mock data based on configuration settings. I ran the server using Node.js 22, Deno 2.0, and Bun 1.2.0.

Benchmark Results (Requests Per Second - RPS)

Runtime	RPS (higher is better)
Node.js 22	30,000
Deno 2.0	38,000
Bun 1.2.0	58,000

Bun 1.2.0 delivered the highest RPS, showcasing its speed advantage.
Deno 2.0 outperformed Node.js significantly, handling more concurrent requests efficiently.
Node.js 22 performed well but was the slowest among the three.

2.3 File System Operations

Bun is optimized for fast file reads and writes.
Deno performs better than Node.js in handling file system tasks due to Rust’s efficiency.
Node.js has good file I/O performance but lags behind Bun and Deno in direct comparisons.

2.4 Package Management Speed

Bun installs and executes npm packages significantly faster than both Deno and Node.js.
Deno has built-in module handling but is slower than Bun for npm compatibility.
Node.js uses npm, which is the slowest in package installation.

3. Benchmarks Summary

The following are updated benchmark results:

Task	Node.js 22	Deno 2.0	Bun 1.2.0
Startup Time	120ms	80ms	5ms
HTTP Requests (RPS)	30k	38k	58k
File Read Speed	50ms	40ms	25ms
npm Package Install	Slow	Moderate	Fast

4. Conclusion

Bun is the fastest in almost every category, making it ideal for performance-intensive applications.
Deno offers better performance than Node.js, particularly in concurrent tasks.
Node.js remains stable but is the slowest of the three.

If performance is your main concern, Bun is the best choice, followed by Deno, with Node.js still being a reliable option for legacy applications.

My custom HTTP server saw a significant performance boost when switching from Node.js 22 to Deno 2.0 and Bun 1.2.0, highlighting how modern runtimes optimize execution and request handling.

DEV Community: Yogesh Rathod