HTTP 226 IM Used vs 421 Misdirected Request
HTTP 226 (IM Used) is a 2xx Success response, while 421 (Misdirected Request) is a 4xx Client Error response. 226 indicates that the server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations. In contrast, 421 means that the request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
Description
The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations.
When You See It
When using delta encoding to reduce bandwidth.
How to Fix
Rarely encountered. The response uses Instance Manipulations (IM) as specified.
Description
The request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
When You See It
With HTTP/2 when a connection is reused for a domain the certificate doesn't cover.
How to Fix
Retry the request on a new connection.
Key Differences
226 is a 2xx Success response, while 421 is a 4xx Client Error response.
HTTP 226: The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations.
HTTP 421: The request was directed at a server that is unable to produce a response for the combination of scheme and authority in the URI.
You encounter 226 when when using delta encoding to reduce bandwidth.
You encounter 421 when with HTTP/2 when a connection is reused for a domain the certificate doesn't cover.
When to Use Which
For 226 (IM Used): Rarely encountered. The response uses Instance Manipulations (IM) as specified. For 421 (Misdirected Request): Retry the request on a new connection.