What Web Server Does Rails Use?


Scott Campbell

When building a web application using Ruby on Rails, one of the essential components is the web server. A web server is responsible for handling incoming requests from clients and serving the appropriate responses. Rails, being a popular framework, provides several options for web servers that developers can choose from based on their specific needs and requirements.


One of the most basic and commonly used web servers with Rails is WEBrick. It comes bundled with Ruby, which means you don’t need to install anything additional to get started. WEBrick is built entirely in Ruby and is easy to set up and configure.

However, while WEBrick is suitable for development purposes due to its simplicity, it may not be the best choice for production environments. It lacks performance optimizations compared to other web servers like Puma or Unicorn.


Puma is a high-performance multi-threaded web server that’s widely used with Rails applications in production environments. It’s designed to handle multiple concurrent requests efficiently by utilizing multiple worker threads.

Puma also supports clustering, which means it can spawn multiple worker processes in addition to threads. This makes it well-suited for applications experiencing heavy traffic and requiring scalability.


Similar to Puma, Unicorn (short for “Unix HTTP Server”) is a popular choice for hosting Rails applications in production. It also utilizes multiple worker processes with shared memory space to handle concurrent requests effectively.

Unicorn differs from Puma in that it does not support multi-threading. Instead, it focuses on process-based concurrency. This makes it a good option when running on systems without thread-safe application code or when using legacy libraries that cannot be run concurrently within threads.

Choosing the Right Web Server

When deciding which web server to use with Rails, it’s important to consider factors such as performance, scalability, and compatibility with your application’s specific requirements.

If you’re in the development phase and looking for simplicity, WEBrick is a great choice. However, for production environments or applications with high traffic, Puma or Unicorn are more suitable options due to their performance optimizations and concurrency models.

  • Puma: Choose Puma if you need multi-threading support and excellent performance.
  • Unicorn: Opt for Unicorn if you prefer process-based concurrency or have specific compatibility requirements.

In conclusion, Rails offers multiple web servers to choose from depending on your needs. Whether it’s WEBrick for simple development purposes or more advanced options like Puma and Unicorn for production environments, selecting the right web server is crucial in ensuring optimal performance and scalability for your Rails application.

Discord Server - Web Server - Private Server - DNS Server - Object-Oriented Programming - Scripting - Data Types - Data Structures

Privacy Policy