HTTP 101 Switching Protocols vs 103 Early Hints
Both HTTP 101 (Switching Protocols) and 103 (Early Hints) belong to the 1xx Informational category. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. Meanwhile, 103 means 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.
説明
The server understands the Upgrade header field request and indicates which protocol it is switching to.
このコードが表示される場合
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
解決方法
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
説明
Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
このコードが表示される場合
When a server wants the browser to start loading CSS/JS before the full response is ready.
解決方法
No fix needed. This optimization helps speed up page loading.
主な違い
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
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.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 103 when when a server wants the browser to start loading CSS/JS before the full response is ready.
どちらをいつ使うか
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 103 (Early Hints): No fix needed. This optimization helps speed up page loading.