When talking to Heroku users, a question that frequently comes up is "when do my apps go to sleep, and why?". Though the behavior is documented in Dev Center, we'd like to provide more immediate visibility into the state of your apps at any given moment.
When an app on Heroku has only one web dyno and that dyno doesn't receive any traffic in 1 hour, the dyno goes to sleep.
When someone accesses the app, the dyno manager will automatically wake up the web dyno to run the web process type. This causes a short delay for this first request, but subsequent requests will perform normally.
Apps that have more than 1 web dyno running never go to sleep and...