HTTP

HTTP 200 OK vs 521 Web Server Is Down

HTTP 200 (OK) is a 2xx Success response, while 521 (Web Server Is Down) is a 5xx Server Error response. 200 indicates that the request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only. In contrast, 521 means that cloudflare-specific. The origin server refused the connection.

Descrição

The request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only.

Quando você o vê

The most common HTTP response — indicates the request was processed successfully.

Como corrigir

No fix needed. The request succeeded as expected.

Descrição

Cloudflare-specific. The origin server refused the connection.

Quando você o vê

When Cloudflare can't establish a TCP connection to the origin server.

Como corrigir

Check that the origin server is running and the firewall allows Cloudflare IPs.

Diferenças principais

1.

200 is a 2xx Success response, while 521 is a 5xx Server Error response.

2.

HTTP 200: The request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only.

3.

HTTP 521: Cloudflare-specific. The origin server refused the connection.

4.

You encounter 200 when the most common HTTP response — indicates the request was processed successfully.

5.

You encounter 521 when when Cloudflare can't establish a TCP connection to the origin server.

Quando usar qual

For 200 (OK): No fix needed. The request succeeded as expected. For 521 (Web Server Is Down): Check that the origin server is running and the firewall allows Cloudflare IPs.

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