How to switch to another Rails version

When you need to use multiple versions of Rails on your computer, how do you switch between them?

Installation rails#

Before I talk about how to switch a version of rails, I will go quickly how to install the different versions of rails. The ruby package manager that I'am using is rbenv and I will use it for this tuto.

If you are using another ruby package manager like rvm, you should look at rbenv and its advantage. rbenv is more lighter and faster than the rvm and rbenv is very recommended by a a lot of developers.

There is an article on dev.to help you understand more clearly: Why and How I Replaced RVM with RBENV.

Ok, now go on our article.

To install whatever version(s) of rails you want:

gem install rails -v 6.0.3.2

To know all rails versions released, you check out on all rails versions.

You can also do it with your terminal with the command line gem list rails --remote --all | grep "^rails ".

I you want to install rails on another version of ruby, you need to switch version of ruby and re-install version of rails.

rbenv install 2.5.1

rbenv global 2.5.1

You can check list gems to see if you installed succesfullly:

gem list --local # result: rails(5.2.4.2,5.2.3)

now you tap rails version to see the current version of rails using, but it shows only

When you install multi version of rails on your machine, it will always take the lastest version of rails. So the question is how can create a new project rails with the version wanted?

Create a project Ruby on Rails with a specific version of rails#

I founded two ways to solve it:

• Using ruby package manager(rbenv)
• Using gem bundler

Using ruby package manager (rbenv)#

rbenv exec rails _<version_rails>_ new my_project

for example:

if i want to create a project with rails 5.2.4.2

rbenv exec rails _5.2.4.2_ new my_project

You can check the version of rails in the Gemfile when the new app has been created:

ruby '2.7.1'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.2.4', '>= 5.2.4.2' #version of rails using to create the project

Using bundler#

The second way is using bundler.

You just do like another gem dependencies. That means you will specify version of rails in your Gemfile.

for example:

source 'https://rubygems.org'
gem 'rails', '6.0.3'

Very simple, isn't it?

Make sure you don't forget bundle install to install all the dependencies from your Gemfile.

And then, what we need to do, just finish with:

rails new new_app

So that is two ways I used. I hope it will be helpful for you.