| Previous | Next |
| HTTP_STATUS_CONTINUE | HTTP_STATUS_PROCESSING |
HTTP_STATUS_SWITCH_PROTOCOLS
HTTP 101 is sent after a successful protocol upgrade, such as a WebSocket upgrade. The protocol change applies only to the current connection, starting after the response header section.
When diagnosing a failed upgrade, compare the client Upgrade and Connection headers with the server response and the server-side protocol configuration. A 101 response itself is success, not an error.
Operational meaning of HTTP 101 for HTTP_STATUS_SWITCH_PROTOCOLS
HTTP 101 (this result) is a informational response. AllStat records its meaning as “101 Switching Protocols”. Interpret it with the request method, selected representation, response headers, and the specification or product that defines the code; the number alone does not prove that application work completed.
Client and server handling
- Keep reading until a final response arrives; this result is not the terminal application result.
- do not commit user-visible success or failure from this informational response.
- record intermediaries because some gateways suppress or transform 1xx responses.
For telemetry, record HTTP 101, method, authority, route template rather than secrets, response headers relevant to caching or retry, latency, upstream identity, and whether the response originated at the application or an intermediary.
Looking for a different code? Search another status or error code.