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).
描述
The server understands the Upgrade header field request and indicates which protocol it is switching to.
何时出现
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
如何修复
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
描述
The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
何时出现
After form submissions to prevent resubmission on browser refresh.
如何修复
Follow the Location header with a GET request. This is intentional — part of the PRG pattern.
主要区别
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.
何时使用哪个
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.