HTTP 101 Switching Protocols vs 431 Request Header Fields Too Large
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 431 (Request Header Fields Too Large) is a 4xx Client Error response. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. In contrast, 431 means that the server refuses to process the request because an individual header field or all headers collectively are too large.
Описание
The server understands the Upgrade header field request and indicates which protocol it is switching to.
Когда вы это видите
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
Как исправить
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
Описание
The server refuses to process the request because an individual header field or all headers collectively are too large.
Когда вы это видите
When cookies accumulate to an excessive size, or a single header (like Authorization) is too long.
Как исправить
Reduce header sizes. Clear excessive cookies. Use shorter tokens.
Ключевые различия
101 is a 1xx Informational response, while 431 is a 4xx Client Error response.
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
HTTP 431: The server refuses to process the request because an individual header field or all headers collectively are too large.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 431 when when cookies accumulate to an excessive size, or a single header (like Authorization) is too long.
Когда что использовать
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 431 (Request Header Fields Too Large): Reduce header sizes. Clear excessive cookies. Use shorter tokens.