Maximum number of domains that can be assigned to one Heroku app?

Question

I am discussing a project with a client who wants his users to access the app via their own domain name if they so choose…

Is there a limit on the number of custom domains that can be assigned to one Heroku application?

Answer 1

There's no limit to the number of domains you can add on an app, from the docs:

You can add any number of domains to a single app

Answer 2

The Heroku docs now state a limit of 1,000 custom domains per app.

Answer 3

The limit is now 10,000 custom domains per-app, according to Heroku's docs.