HTTP 101 Switching Protocols

What 101 means

After a 101 response, the connection stops speaking HTTP/1.1 and continues in the new protocol.

Common causes

• A WebSocket handshake succeeded.
• The client requested an Upgrade the server supports.

How to fix it

1. No action is needed for successful WebSocket connections.
2. If WebSockets fail behind a proxy, allow the Upgrade and Connection headers.

How to check a status code

Enter a URL in the HTTP Status Checker to see its status code, every redirect hop, and response time. For redirect-heavy pages, the Website Speed Test shows how much time redirects add.

FAQ

What does HTTP 101 mean?

101 Switching Protocols is a 1xx informational status code. The server agrees to switch to the protocol requested in the Upgrade header, most often WebSocket.

What causes a 101 error?

A WebSocket handshake succeeded. The client requested an Upgrade the server supports.

How do I fix HTTP 101?

No action is needed for successful WebSocket connections. If WebSockets fail behind a proxy, allow the Upgrade and Connection headers.