101 Switching Protocols

The HTTP 101 Switching Protocols response code indicates a protocol to which the server switches. The protocol is specified in the Upgrade request header received from a client.

The server includes in this response an Upgrade response header to indicate the protocol it switched to. The process is described in the following article: Protocol upgrade mechanism.


101 Switching Protocols


Switching protocols might be used with WebSockets.

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade


Specification Title
RFC 7231, section 6.2.2: 101 Switching Protocol Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

See also