511 Network Authentication Required

Look up a status, pick the right one for an API, or hit a live endpoint that actually returns it. Add ?code=418 to this URL and the response is that status — useful for curl, interceptors, and “what does my client do on 503?” Nothing here phones home except the Try it fetch to this same page.

Which class?

511

Network Authentication Required

Server error · RFC 6585

The client must authenticate to gain network access — captive portals, hotel Wi-Fi intercepts.

When to use

Interception proxies, not origin APIs.

Don’t

Your app’s login is 401. Sending 511 from an origin confuses clients.

Live URL

curl -i https://corecoding.com/utilities/http-status.php?code=511


    

Code use cases