lightmy.dayINSTANT ANSWERS

Informational

HTTP 101: Switching Protocols

HTTP 101 means the server is switching to a different protocol.

Meaning

The server accepted the client's Upgrade request and is changing protocols.

Common causes

Common cases include WebSocket upgrades or HTTP protocol negotiation.

What to check

Check the Upgrade and Connection headers, then confirm the server supports the requested protocol.

Example response

HTTP/1.1 101 Switching Protocols

References

Registry: IANA HTTP Status Code Registry
Spec: RFC 9110 §15.2.2
Guide: MDN 101 Switching Protocols

Related HTTP status codes

Nearby codes often answer the next debugging question.

100 ContinueHTTP 100 means the server received the request headers and the client can continue.103 Early HintsHTTP 103 means the server is sending early hints before the final response.200 OKHTTP 200 means the request succeeded.