How to show console.log() on Heroku?

Question

I've tried to debug my app by using console.log() inside Node.js.

However, I can never see them in heroku log no matter how many lines they show.

$ heroku logs -n 200

This didn't work for me.

Whenever I post something on Heroku server, the log only shows something like:

2018-09-10T02:14:12.731148+00:00 heroku[router]: at=info method=POST path="/users" host=obscure-journey-65698.herokuapp.com request_id=349a44e8-5fd7-46a2-aacb-75e51503109c fwd="73.67.204.217" dyno=web.1 connect=1ms service=355ms status=400 bytes=216 protocol=https

The console log never shows up! They do log the information I want when running npm start.

Thanks for any help.

Answer 1

go to the heroku website and open your deployed app. go the more tab to the right corner and open logs. At log tab you will see the console outputs. you will see the console outputs of the file which is written in procfile or the file which is the first to execute. For example if have written in procfile that: web: node server.js then the server.js file will be the first one to execute. so if i have written console.log("output") in my server.js file then the output will be shown in logs of heroku which is in more tab as described above. Thanks