5xx Server errors
511 Network Authentication Required
You need to sign in to the network first.
Common causes
- Hotel, airport or café Wi-Fi with a sign-in page.
How to fix it
- Open any website in a browser to get the network's sign-in page.
Find out the moment your site returns 511
Spot Downtime monitors count this as down and alert you, since visitors see an error. (The public “Is it down?” checker treats 4xx answers from big sites as online, because many refuse automated requests.)