Heroku: How can you check Heroku Error Logs?

Simply use heroku logs to display the last 100 lines of your logs.

Or to tail the logs in real-time: heroku logs -t

Heroku only saves the last 1500 lines of logs, which you can access using heroku logs -n 1500. If you want more logging, check out Heroku add-ons like Logentries or Papertrail.

$ heroku logs -t --app app-name

This gives you all current logs (logentries add-on would be used)

heroku logs --tail

With above command you can see continuous heroku logging.