101 Switching Protocols
This is an educational reference page about HTTP 101 Switching Protocols. The page itself is served as 200 OK so it can be indexed as HTTP documentation.
The requester has asked the server to switch protocols and the server has agreed to do so.
Specification
Registered in the IANA HTTP Status Code Registry as Switching Protocols. Defined in RFC 9110, Section 15.2.2.
Header and content rules
What RFC 9110 says about a 101 response, quoted from the RFC. The 1xx class rules also apply.
- MUST (server; Upgrade): Send Upgrade naming the protocol or protocols in effect after this response. Table row
The server MUST generate an Upgrade header field in the response that indicates which protocol(s) will be in effect after this response. RFC 9110 §15.2.2
The same rule is in the response obligations table and its JSON.