Is Ruby installed?

How to check if Ruby is installed on a Mac

Question: Is Ruby installed on my Mac? Does Ruby come installed on a Mac?

To find out is Ruby installed?, just enter in your terminal application:

$ ruby -v

Don't type the $ character. The $ character is just a cue that you should enter a shell command.

If Ruby is not installed, you'll see:

zsh: command not found: ruby

The which command will confirm that Ruby is missing:

$ which ruby
ruby not found

You can use the which command with flag -a to see if more than one Ruby executable is installed:

$ which -a ruby
/Users/daniel/.asdf/shims/ruby
/usr/bin/ruby

If Ruby is installed, the ruby -v command will show a response like:

$ ruby -v
ruby 3.4.1p0

MacOS comes with a "system Ruby" pre-installed. Use the which command to see if you are using the system Ruby:

$ which ruby
/usr/bin/ruby

If you see /usr/bin/ruby, it is the pre-installed macOS system Ruby. It's a bad idea to use the Mac system Ruby. See the article Do not use the MacOS system Ruby. That's why developers use a version manager such as asdf, chruby, rbenv, or rvm. A version manager can also help if you're juggling multiple projects that can't be updated all at once.

For a guide that compares version managers and shows the best way to install Ruby, see Install Ruby on a Mac.