511 Network Authentication Required
5xx Server error
You must sign in to the network first — the usual sight on public Wi-Fi.
| On the wire | HTTP/1.1 511 Network Authentication Required |
|---|---|
| Code | 511 |
| Is it an error | Yes — this is an error |
| Category | 5xx Server error |
The problem is on the server side; retrying later is often worth it.
How to read this
- The first digit of a status code carries the meaning: 4 means the request, 5 means the server.
- 404 means "not there"; 403 means "there, but not for you". Swapping them makes debugging slower.
- Header names are case-insensitive — Content-Type and content-type are the same header.
- Caching and CORS problems usually come down to one header line, visible in the browser’s network tab.
Frequently asked questions
Q. What does HTTP 511 Network Authentication Required mean?
You must sign in to the network first — the usual sight on public Wi-Fi.
Q. What does 511 Network Authentication Required look like on the wire?
It travels as HTTP/1.1 511 Network Authentication Required
Q. Is 511 Network Authentication Required an error?
Yes. A code starting with 4 blames the request; one starting with 5 blames the server.
Q. What group does 511 Network Authentication Required belong to?
The 5xx server error group; the rest of that group is listed further down.