DEV Community

Cover image for Informational status codes
Emilie Gervais
Emilie Gervais

Posted on • Updated on


Informational status codes

Preface: A HTTP status code is issued from the server in response to a client's request made to the server. The five status code response classes are informational, successful, redirection, client error and server error.

Informational status codes

Informational status codes indicate that the request initiated by the browser was received and is continuing.

Table Of Contents

100 Continue

Definition: The request has been received and has not yet been rejected by the server. The server intends on sending a final response once the request has been completed meaning that the server has received the request headers and client can now proceed to send the request body. To have a server check the request's headers, a client must send Expect: 100-continue as a header in its initial request and receive a 100 Continue status code in response before sending the body.

100 Continue is defined in RFC 7231.

101 Switching Protocols

Definition: The request has asked the server to switch protocols. The server response indicates that it is switching protocol as requested. In this response, the server includes an Upgrade response header to indicate the protocol it switched to.

101 Switching Protocols is defined in RFC 7231.

102 Processing

Definition: The request has been received and is being processed by the server, but no response is available yet. In the meantime, this response prevents the client from timing out and assuming the request was lost.

102 Processing is defined in RFC 2518.

103 Early Hints

Definition: The server is likely to send a final response with the header fields included in the informational response. Mainly intended to be used with the Link header to allow the user agent to start preloading resources while the server is still preparing a response.

103 Early Hints is defined in RFC 8297.

Unofficial and customized non-standard responses defined by server softwares are not included in the list above.


Top comments (2)

artoodeeto profile image

question about status code. on the backend are you using everything? on our server we're just using 400-404. just wondering. hehe

hexangel616 profile image
Emilie Gervais

I don't use all of them either, but they are all available if needed! =)