HTTP 511 Network Authentication Required

The client needs to authenticate to gain network access (e.g., captive portal).

What 511 means

HTTP 511 Network Authentication Required indicates the client needs to authenticate with the network (not the origin server). This is commonly seen in captive portals — WiFi networks at hotels, airports, or coffee shops that require login before granting internet access.

Common causes

• Captive portal requiring authentication
• Corporate network requiring sign-in
• WiFi hotspot requiring terms acceptance

How to fix it

• Authenticate with the network portal
• This is not a website issue — it's a network access issue

SEO impact

No SEO impact. This is a network-level response, not served by your origin server.

Monitoring tip

If LemWatch detects 511 from your monitoring endpoints, it indicates a network issue at the monitoring location, not a problem with your site.