Installing and Using Gems
Discover how to install gems using gem install and include them in your projects.
Installing and Using Gems is a free Ruby Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Ruby Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
1
Installing and Using Gems
Ruby gems allow developers to easily add functionality to their applications.
In this lesson, you will learn how to install and use gems in your Ruby projects.
2
Installing a Gem
Use the gem install command to install a gem.
gem install nokogiri3
Requiring a Gem in Your Code
After installing a gem, you must require it in your Ruby script.
require 'nokogiri'
puts 'Nokogiri gem loaded successfully!'4
Installing a Specific Version of a Gem
You can install a specific gem version by specifying it.
gem install rails -v 6.1.45
Uninstalling a Gem
To remove an installed gem, use:
gem uninstall nokogiri6
Updating All Gems
To update all installed gems to the latest versions, run:
gem update7
Checking a Gem’s Usage
To find out where a gem is installed and its details, use:
gem which nokogiri8
9
Installing Gems Globally or Locally
By default, gems are installed globally. To install a gem for a specific user only, use:
gem install nokogiri --user-install10
Congratulations!
You have learned how to install, use, and manage Ruby gems.
Next, you will explore how to manage gem dependencies with Bundler.
Frequently asked questions
Is the “Installing and Using Gems” lesson free?
Yes — the full text of “Installing and Using Gems” is free to read here on the web, and the Ruby Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Ruby Academy course, upgrade to CoddyKit PRO.
What will I learn in “Installing and Using Gems”?
Discover how to install gems using gem install and include them in your projects. You practise Ruby Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Ruby Academy?
No prior experience is required. Ruby Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Installing and Using Gems” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Ruby Academy lesson?
Yes. Every Ruby Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- What Are Gems?
- Installing and Using Gems
- Managing Dependencies with Bundler
- Creating Your Own Gem