HTTP 101 Switching Protocols vs 303 See Other
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 303 (See Other) is a 3xx Redirection response. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. In contrast, 303 means that the server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
คำอธิบาย
The server understands the Upgrade header field request and indicates which protocol it is switching to.
เมื่อคุณพบเห็น
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
วิธีแก้ไข
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
คำอธิบาย
The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
เมื่อคุณพบเห็น
After form submissions to prevent resubmission on browser refresh.
วิธีแก้ไข
Follow the Location header with a GET request. This is intentional — part of the PRG pattern.
ความแตกต่างหลัก
101 is a 1xx Informational response, while 303 is a 3xx Redirection response.
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
HTTP 303: The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 303 when after form submissions to prevent resubmission on browser refresh.
ควรใช้อันไหนเมื่อไร
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 303 (See Other): Follow the Location header with a GET request. This is intentional — part of the PRG pattern.