My app is displaying a 502 or 503 "Unavailable" error. What should I do?

First, check your app's status. If you see a "Failing" status, see How can I fix a Failing status?

If you have just published or updated your app, a 502 or 503 error is not unusual for the first minute or so. This occurs because the app needs a few moments to start.

A 502 or 503 error can also appear as a result of automatic checks that Plotly Cloud performs on your apps. If Plotly Cloud needs to optimize the resources available to your app, you may see a 502 or 503 error for approximately 10 seconds. We recommend waiting a short time and then refreshing.