Server error · HTTP reference

511Network Authentication Required

Network access requires authentication, such as signing in through a captive portal.

511 concerns network access authentication. It is different from an application requesting login with 401.

The company behind the code.

For Wi-Fi access and network authentication.

511Network Authentication Required

Network access requires authentication, such as signing in through a captive portal.

Available

For Wi-Fi access and network authentication.

Your logo, your message, your corner of the internet.

Try the response.

Returns this HTTP status with the current sponsor’s name, advertising message and website. Useful for testing how your app handles a response.

GET /responses/511Open response RFC 6585, section 6

This is an independent project. Sponsorship does not confer ownership of HTTP standards.

Understanding 5xx responses.

Server error responses describe failures in the server or its upstream services.

Inspect server and gateway logs, and check service availability. Retrying requests that change data can duplicate an operation unless the API supports safe retries.

Reference reviewed 5 September 2026. How we use sources.

Related status codes.

Browse all 60 codes