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).
설명
The server understands the Upgrade header field request and indicates which protocol it is switching to.
이 코드를 보게 되는 경우
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
해결 방법
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
설명
The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
이 코드를 보게 되는 경우
After form submissions to prevent resubmission on browser refresh.
해결 방법
Follow the Location header with a GET request. This is intentional — part of the PRG pattern.
주요 차이점
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.
언제 어떤 것을 사용할지
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.