The official Rails upgrading guides will usually describe their Ruby version support as X.Y or newer. In some situations, I want to verify which Ruby versions the Rails version is actually tested against e.g.

  • I am upgrading an old Rails app and want to find out where the Ruby version support stops
  • I am considering upgrading to a very new version of Ruby and want to verify that Rails is actually testing against it.

This is what I currently do:

  1. Go to and find the name of the branch which corresponds to my rails version - it’ll be something like 7-0-stable or 6-1-stable
  2. Find the CI page for that branch by filling the branch name into<YOUR_BRANCH_NAME> e.g.
  3. You can see which Ruby versions are tested in the summary of each build Rails CI snapshot