A Ruby application is detected when it has a Gemfile file in the root
directory. If your application has no dependencies, it should include an empty
Gemfile file.

MRI Ruby versions

All MRI Ruby versions 1.9+ and 2.+ are supported. Newer versions are
automatically compiled on-demand if you ask for them.

Your version will either default to 2.3.4, or the version you've specified in your Gemfile. For instance:

cat Gemfile
source ""

ruby "2.3.0"

# rest of your Gemfile

The most recent versions we officially support are as follow:

Ruby version Rubygems version
2.4.1 patchlevel 111 2.6.11
2.3.4 patchlevel 301 2.5.2
2.2.7 patchlevel 470

Generally, you should follow the guidelines outlined in this Heroku article.

JRuby versions

JRuby versions are no longer supported at the moment.

Example applications

  • OpenProject, the web-based project management system.
  • Gitlab, the Open source software to collaborate on code.
  • Discourse, the platform for community discussion.
  • example-sinatra-app, a really simple sinatra app to get you started.