Chapter 2: Installing Ruby and Rails

Before you can build Rails applications, you need Ruby and Rails installed on your computer. The installation steps are slightly different on Windows, macOS, and Linux, but the core idea is the same: install Ruby first, then install Rails as a gem.

In this chapter, you will install Ruby and Rails, and verify the installation with a few simple commands.

🖥️ Installing Ruby

On Windows, download and run RubyInstaller from the official Ruby website and accept the default options. On macOS or Linux, the easiest way is to use a version manager such as RVM or rbenv so you can switch Ruby versions easily.

# macOS / Linux (using rbenv)
brew install rbenv ruby-build
rbenv install 3.3.0
rbenv global 3.3.0

# Check the Ruby version
ruby --version

🚀 Installing Rails

Once Ruby is installed, open your terminal and install Rails with the Ruby gem command:

gem install rails

This installs Rails and all of its dependencies. Depending on your internet speed this may take a few minutes.

✅ Verifying the Installation

After the installation finishes, check the version to confirm everything is working:

rails --version

You should see a message such as Rails 7.1.x or newer. You can also check that Ruby and SQLite (the default database) are available:

ruby --version
sqlite3 --version

🏠 Practice Exercises

# 1. Check your Ruby version
ruby --version

# 2. Install Rails (if not already installed)
gem install rails

# 3. Confirm Rails is ready
rails --version

When rails --version prints a version number, you are ready to create your first Rails application in the next chapter.