How to debug a Node.JS application?

The error page displayed in the web browser is, by default, quite basic. It is possible to enable a more advanced debugging mode in Phusion Passenger to display more detailed errors by adding the following lines to the .htaccess file at the root of the domain (and subdomain if applicable):

PassengerAppEnv development

PassengerFriendlyErrorPages onYou can also easily create a "Hello World" application to check whether the issue comes from your code or from the server.

Updated on: 14/02/2026