Heroku-18 stack is now generally available

Change effective on 24 July 2018

Heroku-18, our stack based on Ubuntu 18.04 Long Term Support, is now generally available. It will be supported through April 2023.

If your organization uses review apps, we recommend testing Heroku-18 by defining your stack in app.json:

   "stack": "heroku-18"

You can then upgrade your app by running:

$ heroku stack:set heroku-18

Learn more about the Heroku-18 stack, as well as how to test it with your app.