HTTP 103 Early Hints vs 521 Web Server Is Down
HTTP 103 (Early Hints) is a 1xx Informational response, while 521 (Web Server Is Down) is a 5xx Server Error response. 103 indicates that used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response. In contrast, 521 means that cloudflare-specific. The origin server refused the connection.
คำอธิบาย
Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
เมื่อคุณพบเห็น
When a server wants the browser to start loading CSS/JS before the full response is ready.
วิธีแก้ไข
No fix needed. This optimization helps speed up page loading.
คำอธิบาย
Cloudflare-specific. The origin server refused the connection.
เมื่อคุณพบเห็น
When Cloudflare can't establish a TCP connection to the origin server.
วิธีแก้ไข
Check that the origin server is running and the firewall allows Cloudflare IPs.
ความแตกต่างหลัก
103 is a 1xx Informational response, while 521 is a 5xx Server Error response.
HTTP 103: Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
HTTP 521: Cloudflare-specific. The origin server refused the connection.
You encounter 103 when when a server wants the browser to start loading CSS/JS before the full response is ready.
You encounter 521 when when Cloudflare can't establish a TCP connection to the origin server.
ควรใช้อันไหนเมื่อไร
For 103 (Early Hints): No fix needed. This optimization helps speed up page loading. For 521 (Web Server Is Down): Check that the origin server is running and the firewall allows Cloudflare IPs.