511
Network Authentication Required
5xx Server error
Class
RFC 6585
Defined in
What does HTTP 511 mean?
The client must authenticate to gain network access. Used by captive portals in hotels, airports and cafés to signal that you need to log in to the Wi-Fi before browsing.
5xx Server error: The request looked valid, but the server failed to fulfil it. The fix is on the server side.
How to fix 511 Network Authentication Required
- Open any page and complete the network login.
511 and SEO
No SEO impact — it is generated by the network, not your site.
Example response
HTTP/1.1 511 Network Authentication RequiredRelated status codes
- 401 Unauthorized — Authentication is required and has failed or not been provided.
Check which status code a URL returns with the HTTP header checker.
All HTTP status codesSearch the full list of status codes from 100 to 599 with their meanings and SEO impact.
Open the full list Frequently asked questions
What does status code 511 mean?
511 Network Authentication Required: The client must authenticate to gain network access.
How do I fix a 511 error?
Open any page and complete the network login.
Does 511 affect SEO?
No SEO impact — it is generated by the network, not your site.