HTTP 501 Not Implemented vs 522 Connection Timed Out
Both HTTP 501 (Not Implemented) and 522 (Connection Timed Out) belong to the 5xx Server Error category. 501 indicates that the server does not support the functionality required to fulfill the request. The server either does not recognize the request method or lacks the ability to fulfill it. Meanwhile, 522 means that cloudflare-specific. TCP connection to the origin server timed out.
Description
The server does not support the functionality required to fulfill the request. The server either does not recognize the request method or lacks the ability to fulfill it.
When You See It
When using an HTTP method (like PATCH) that the server doesn't support.
How to Fix
Use a different HTTP method that the server supports. Check server documentation.
Description
Cloudflare-specific. TCP connection to the origin server timed out.
When You See It
When the origin server is overloaded or network issues prevent connection.
How to Fix
Check origin server health. Verify firewall rules. Check for network congestion.
Key Differences
HTTP 501: The server does not support the functionality required to fulfill the request. The server either does not recognize the request method or lacks the ability to fulfill it.
HTTP 522: Cloudflare-specific. TCP connection to the origin server timed out.
You encounter 501 when when using an HTTP method (like PATCH) that the server doesn't support.
You encounter 522 when when the origin server is overloaded or network issues prevent connection.
When to Use Which
For 501 (Not Implemented): Use a different HTTP method that the server supports. Check server documentation. For 522 (Connection Timed Out): Check origin server health. Verify firewall rules. Check for network congestion.