status Registered
Verified 2026-09-18 · registry updated 2025-09-15

HTTP 511 Network Authentication Required

The client must authenticate to gain network access through an intercepting network intermediary.

Use 511 for captive portals or network access control, not ordinary origin-server application login.

httpstatus codenetworkauth

Response (http)

HTTP/1.1 511 Network Authentication Required

Use 511 for captive portals or network access control, not ordinary origin-server application login.

Common mistakes

  • Using 511 for application login; it is for captive-portal network authentication only.

Registry reference: rfc6585

Permalink: https://merginit.com/reference/http/status-511