Heroku websocket connection

Question

I'm building an app to be hosted on heroku default service level like my_app.herokuapp.com which should open a websocket. Since domain is https:// I have to use wss:// in order to forward requests.

Problem is that the connection fails after 3 seconds

failed: Error in connection establishment: net::ERR_CONNECTION_CLOSED

In the SSL-endpoint documentation page I can read

All default appname.herokuapp.com domains are already SSL-enabled and can be accessed by using https, for example, https://appname.herokuapp.com.

but in my_app detail page there is

SSL - Upgrade to paid dynos to configure Heroku SSL

I smell this could be the reason why the connection cannot be established but since these sentences seems contradictory I would like to understand better the matter.

I thought that since I'm using a subdomain the SSL is enabled but perhaps I need to upgrade to paid dyno in order to configurate it.

If this can be the deal my solution would be to upgrade to hobby license (7$/month) which ensures the

FREE SSL for custom Domains.

Am I missing something or this could be the reason?

Answer 1

According to https://devcenter.heroku.com/articles/ssl:

Heroku SSL is included for free on any app that uses paid dynos

This is weasel language; it's not really free unless you're already paying for it.