HTTP 201 Created vs 521 Web Server Is Down
HTTP 201 (Created) is a 2xx Success response, while 521 (Web Server Is Down) is a 5xx Server Error response. 201 indicates that the request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity. In contrast, 521 means that cloudflare-specific. The origin server refused the connection.
Description
The request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity.
When You See It
After successfully creating a new user, post, order, or other resource via a REST API.
How to Fix
No fix needed. Check the Location header for the URL of the new resource.
Description
Cloudflare-specific. The origin server refused the connection.
When You See It
When Cloudflare can't establish a TCP connection to the origin server.
How to Fix
Check that the origin server is running and the firewall allows Cloudflare IPs.
Key Differences
201 is a 2xx Success response, while 521 is a 5xx Server Error response.
HTTP 201: The request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity.
HTTP 521: Cloudflare-specific. The origin server refused the connection.
You encounter 201 when after successfully creating a new user, post, order, or other resource via a REST API.
You encounter 521 when when Cloudflare can't establish a TCP connection to the origin server.
When to Use Which
For 201 (Created): No fix needed. Check the Location header for the URL of the new resource. For 521 (Web Server Is Down): Check that the origin server is running and the firewall allows Cloudflare IPs.