The JavaScript ecosystem has been undergoing a massive transformation in recent years, both on the browser side and the server side. Especially the increasing performance expectations of modern web applications, the rise of TypeScript, the proliferation of microservice architectures, and the standardization of libraries like React/Vue have accelerated JavaScript's development pace even further. The most important pillar of this growth was Node.js, which had long been the sole ruler of server-side JavaScript. With its huge community, strong ecosystem, and millions of packages, Node.js is still seen as one of the most mature solutions in the industry. However, as the needs of web technologies change, Node.js's traditional structure, due to some limitations, is beginning to no longer be the only option.

At this point, Bun, which entered the stage, has created great excitement in the JavaScript community. Because Bun is not just a "Node alternative"; it is described as a completely modern runtime with its performance, minimal design, straightforward configuration process, and integrated toolkit it offers developers. Whereas before, tools like a package manager, bundler, test runner, and TypeScript transpiler had to be installed separately, Bun brings all these components together on a single powerful platform. This both speeds up development processes and significantly reduces project complexity.

Especially for teams developing TypeScript, React, serverless architecture, microservice structures, and real-time web applications, Bun stands out with its extraordinary performance. Applications compiling faster, starting up faster, consuming far less memory, and offering a modern developer experience make it the strongest and most ambitious JavaScript runtime of recent times.

In this article, we will address all critical questions such as "What is Bun?", "What are the differences between it and Node.js?", "How does it affect real-world project development processes?", "In which projects should it be preferred?", and "Where should we be cautious?" in a detailed and understandable way. If you work professionally with JavaScript—whether backend, full-stack, or React side—this comparison contains important information that directly affects you.

What is Bun?
Bun is an "all-in-one" development tool and runtime built for JavaScript and TypeScript. It packs many capabilities like a runtime, package manager, bundler, test runner, HTTP/WebSocket server, and database drivers into a single file.

In short:
Node.js + npm/Yarn + Webpack/Vite + Jest + ts-node → Bun as a single tool.

Core features of Bun:

• Ultra-fast package manager that installs packages with a single command (bun install)

• Directly runs TypeScript and JSX

• Built-in HTTP and WebSocket server

• Built-in PostgreSQL, MySQL, SQLite support

• Built-in test runner (bun test)

• Bundler similar to Vite/webpack is ready

• Lower resource consumption and high speed as it's written in Zig

• Compatible with modern web APIs

Why is Bun So Popular?
There are several fundamental reasons for Bun's rapid spread among developers:

1. Extraordinary Performance
Bun is significantly faster than Node.js in both startup time and HTTP performance.
For example, there can be a difference of thousands of requests/second in a simple web server.

The reason for this:

• Written in the Zig language

• Uses the JavaScriptCore engine (Safari/WebKit)

• Uses memory more efficiently

• Optimized IO and file operations

2. Zero Configuration
TypeScript, JSX, React, modern JS features... They work in Bun without any setup.

In Node.js, however, many configurations are required such as:

• tsconfig

• babel config

• webpack/vite config

• jest config

• package.json script complexity

3. Full Ecosystem with a Single Tool
While Node.js projects require installing at least 4-5 tools, one tool is enough with Bun:

4. Cleaner Project Structure
When using Bun, problems like dozens of config files, complex dependency chains, and hundreds of megabytes of node_modules in the project directory are significantly reduced.

Disadvantages and Risks of Bun
Like any powerful technology, Bun also has some limitations:

1. Ecosystem Not Yet as Mature as Node.js
Node.js has been in production for 15 years and has millions of packages.
Since Bun is new:

• Some modules can be incompatible

• Issues can arise with native modules

• Could be risky in large enterprise projects

2. Some Node APIs Not Fully Stable
Although improving with each version, 100% Node.js compatibility is not yet achieved.

3. Might Be Early for Large and Critical Projects
Because Bun is a new and rapidly evolving project:

• Long-term support guarantees are not fully clear

• Unexpected errors may occur in critical systems

4. Uses Different Approaches from Standards
Due to technological choices like its Zig-based structure and JavaScriptCore usage, differences may be seen in some edge-case behaviors.

Why is Node.js Still Strong?
Node.js is the most reliable server-side platform in the JavaScript world.

Advantages:

• Very wide package ecosystem (npm)

• Huge community

• Very high production experience

• Enterprise support and sustainability

• Tested in millions of live projects

• Higher compatibility with native modules

Therefore, it is still the first choice, especially for large-scale and long-term projects.

Bun vs Node.js: The Simplest and Clearest Differences
The table below summarizes the differences in a very understandable way:

In Which Projects Should Bun Be Used?
✓ Projects that need to start quickly
Perfect for MVP, prototype, startup operations.

✓ React + TypeScript projects
Very fast with zero config.

✓ Serverless functions
Provides a big advantage thanks to fast startup.

✓ WebSocket / real-time applications
Built-in WebSocket support is quite strong.

✓ Small–medium scale API services
Performance and low configuration make it ideal.

✓ Independent microservices
No separate configuration needed for each service.

In Which Projects Should Node.js Be Preferred?
✓ Enterprise projects
Node.js is still more stable for long-term work.

✓ Packages with native dependencies
For example, PDF, image processing, low-level socket modules.

✓ Continuation of existing large projects
Migration cost may be high.

✓ Projects needing very specific third-party packages
Compatibility issues may be encountered with Bun.

Which One Should You Choose?
Bun is a candidate to be the future JavaScript runtime.
Fast, simple, modern, and developer-friendly.

But Node.js is still the most reliable and mature option.

Realistic recommendation:

• If starting new projects → Try Bun

• In critical production projects → Don't abandon Node.js

• Work in a hybrid structure → Some microservices could be on Bun, the main project could be on Node.js/PHP

This way, you get the speed advantage without taking risks.

Bun Installation and Run Guide (macOS, Linux, Windows)
Bun, the rising star of the modern JavaScript ecosystem, draws attention with its easy installation and high performance. In the guide below, you can find in detail how to install and run Bun on all platforms.

1. Bun Installation on macOS (Intel & Apple Silicon)
Bun is one of the platforms that works most problem-free on macOS. Performance is even higher on Apple Silicon (M1, M2, M3) devices.

1.1. Installation from Terminal (Recommended Method)
Open Terminal and run this command:

bash

curl -fsSL https://bun.sh/install | bash

When installation is complete, the terminal automatically updates PATH settings. If the command is not recognized when you open a new terminal:

bash

source ~/.bashrc

1.2. Verifying Installation

bash

bun --version

If the version number appears, installation is complete.

1.3. Running the First Bun Application
A simple HTTP server:

bash

bun init
bun run index.ts

Or one-time:

bash

bun run https://bun.sh/examples/hello.ts

2. Bun Installation on Linux
All modern Linux distributions, including Ubuntu, Debian, CentOS, Fedora, and Arch Linux, are supported.

2.1. Installation via Terminal Command
Linux installation is the same as macOS:

bash

curl -fsSL https://bun.sh/install | bash

Reload PATH variable after installation:

bash

source ~/.bashrc

If using Zsh:

bash

source ~/.zshrc

2.2. Installation via Snap or apt (Not Recommended)
Bun officially recommends installation via its own script rather than a package manager. Therefore, the most stable method is installation via curl.

2.3. Testing Installation

bash

bun --version

2.4. Running the First Project

bash

mkdir bun-test
cd bun-test
bun init
bun run index.ts

3. Bun Installation on Windows (WSL and Native)
Bun can be run on Windows in two different ways:

• Via WSL 2 (RECOMMENDED)

• Directly Windows native (New native support arrived)

I explain both methods step by step.

3.1. Method 1 — Windows Native Installation (Clean)
Open PowerShell from programs:

powershell

powershell -c "irm bun.sh/install.ps1 | iex"

3.2. Method 2 — Bun Installation via WSL 2 (Recommended)
The environment where Bun works with full performance and without problems is the WSL 2 + Ubuntu combination.

Step 1: Enable WSL
Open PowerShell as administrator:

powershell

wsl --install

This command automatically downloads and installs Ubuntu.

Step 2: Open Ubuntu Terminal
From Start menu:
Ubuntu → Open

Step 3: Perform Bun Installation
In Ubuntu terminal:

bash

curl -fsSL https://bun.sh/install | bash

Step 4: Verify Installation

bash

bun --version

Step 5: Start Project

bash

bun init
bun run index.ts

3.3. Method 3 — Windows Native Installation (New)
Bun can now also work natively on Windows. Although this method is still in development, it's stable enough for many projects.

Step 1: Installation with Chocolatey (Recommended)
First install Chocolatey if not present:
Open PowerShell as administrator:

powershell

Set-ExecutionPolicy AllSigned

Then:

powershell

Set-ExecutionPolicy Bypass -Scope Process -Force; `
[System.Net.ServicePointManager]::SecurityProtocol = `
   [System.Net.ServicePointManager]::SecurityProtocol `
   -bor 3072; `
iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))

After Chocolatey is installed, install Bun:

powershell

choco install bun -y

Step 2: Test Installation

bash

bun --version

Step 3: Create Project

bash

bun init
bun run index.ts

Bun "Hello World" HTTP Server Example
Works on all platforms:

typescript

// index.ts
export default {
  port: 3000,
  fetch() {
    return new Response("Hello Bun!");
  },
};

Run:

bash

bun run index.ts

Open in browser:

text

http://localhost:3000

Summary Table: Installation by Platform

You can find more detailed information about Bun on its own site at bun.com.