101 Switching Protocols
1xx Informational. The server agrees to switch protocols as requested by the client, e.g. from HTTP to WebSocket.
1xx Informational
What it means
The server agrees to switch protocols as requested by the client, e.g. from HTTP to WebSocket.
Common causes
Returned when a client sends an "Upgrade" header requesting a protocol change, typically for WebSocket connections.
How to fix it
Informational only — expected during a WebSocket handshake or protocol upgrade.
Frequently asked questions
What does HTTP 101 mean?
The server agrees to switch protocols as requested by the client, e.g. from HTTP to WebSocket.
What causes a 101 Switching Protocols?
Returned when a client sends an "Upgrade" header requesting a protocol change, typically for WebSocket connections.
How do I fix a 101 error?
Informational only — expected during a WebSocket handshake or protocol upgrade.
Other 1xx Informational codes
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