Informational responses

The HTTP status codes in the range 100 to 199 are informational codes. They are used by the server to tell the client that the request has been received and that more information will follow. These codes are usually not of particular interest to most users, as they only indicate that the request has been received and that further steps need to be taken before a full response is returned. However, they are used by application and web developers to monitor the status of requests and responses and to diagnose problems that may occur during communication between the client and server.

<100/> Continue

The customer can continue the request

<101/> Switching Protocols

The transmission protocol is changed at the request of the client

<102/> Processing

a time-consuming request is processed
Official Deprecated

<103/> Early Hints

The server prepares a response

<110/> Response is Stale

the response provided by a cache is outdated
Official Deprecated

<111/> Revalidation Failed

the cache was not able to validate the response because the origin server could not be reached
Official Deprecated

<112/> Disconnected Operation

the cache is intentionally disconnected from the rest of the network
Official Deprecated

<113/> Heuristic Expiration

the cache has heuristically chosen a freshness time greater than 24 hours and the age of the answer is greater than 24 hours
Official Deprecated

<199/> Miscellaneous Warning

arbitrary, unspecific warning
Official Deprecated