Connectivitycheck Gstatic Generate 204 ((exclusive)) Jun 2026

Do not block or alter responses to this endpoint in enterprise networks, as it degrades user experience on Android and Chromium devices without improving security.

Here is how the handshake works:

| Platform | Purpose | |----------|---------| | | Primary captive portal detection and connectivity monitor (see NetworkMonitor class) | | ChromeOS | Same as Android; used in Shill connection manager | | Chromium Browsers | Detects if a network requires authentication before allowing background sync or updates | | Network Testing Tools | curl -I http://connectivitycheck.gstatic.com/generate_204 | | Custom Scripts | Used in routers/embedded systems to verify WAN connectivity | connectivitycheck gstatic generate 204

This simple test is useful for various applications, such as: Do not block or alter responses to this

: Network allows this specific Google endpoint (whitelisted) but blocks other traffic. Fix : Test with a different URL, e.g., http://www.google.com/generate_204 The specific logic relies entirely on standard HTTP

To verify this, Google devices immediately send a background HTTP/HTTPS GET request to http://connectivitycheck.gstatic.com/generate_204 . The specific logic relies entirely on standard HTTP status codes:

The "generate_204" URL is a special endpoint that serves a very specific purpose. When a device requests this URL, the server responds with a simple HTTP response containing a 204 status code, which means "No Content." In other words, the server doesn't send any actual content, just an acknowledgement that the request was received and processed.