HTTP response status codes show whether or not a particular HTTP request (which is sent by the clients) was successfully completed. When a client sends a request to the server, the server responds with a status code.
There are five groups or categories of HTTP response status codes.
- 1xx (100–199) Informative Response – Request has been received and is being processed.
- 2xx (200–299) Accepted/Successful – The request was received, understood, and accepted successfully.
- 3xx (300–399) Redirection Message – Additional steps are needed to complete the request.
- 4xx (400–499) Client Error – The request has incorrect syntax or is unable to be fulfilled.
- 5xx (500–599) Server Error – A legitimate request was reportedly not fulfilled by the server.
Table of Contents
Informative Response (100 – 199)
Continue – HTTP Status code 100
The HTTP Status code 100 determines whether or not the client should proceed with the request. Whether or not the client should ignore the response.
Switching Protocols – HTTP Status code 101
The HTTP status code 101 indicates that the requester has requested and the server has agreed to switch protocols.
Processing – HTTP Status code 102
The request has already been sent (the server has received the request) and is being processed, but no response has yet been returned.
Accepted/Successful (200 – 299)
OK – HTTP Status code 200
The HTTP status code 200 is a success response code that signals that the request has been completed successfully.
Created – HTTP Status code 201
When the request is finished and a new resource is created, the HTTP status code 201 is returned.
Accepted – HTTP Status code 202
HTTP status code 202 is issued when the request for processing is accepted but processing is still in progress.
No Content – HTTP Status code 204
When we send a request to the server for processing, the server completes it but does not return any content.
Redirection Message (300 – 399)
Moved Permanently – HTTP Status code 301
The HTTP Status code 301 is related to the URL. If the requesting resource’s URL has been permanently altered. The response includes the updated URL.
Found – HTTP Status code 302
The page you requested has been relocated to a new location for the time being.
Not Modified – HTTP Status code 304
The HTTP status code 304 is used while caching. This status code informs the client that the response has not been updated for the request and that they can continue to use the cached version of the response.
Client Error (400 – 499)
Bad Request – HTTP Status code 400
If the server is unable to interpret the request, the HTTP status code 400 is given.
Unauthorized – HTTP Status code 401
If the request necessitates the use of a username and password to authenticate the user. Furthermore, this information is not included in the request. The HTTP status code 401 is returned in this instance.
Forbidden – HTTP Status code 403
If the client desires to access the content but does not have the necessary permissions.
Not Found – HTTP Status code 404
The HTTP status code 404 indicates that the server was unable to locate the requested resource.
Server Error (500 – 599)
Internal Server Error – HTTP Status code 500
If there is an unwanted circumstance that is not addressed and no appropriate message is available. The HTTP status code 500 is returned in this instance.
Bad Gateway – HTTP Status code 502
If the request was not completed, if the server is serving as a gateway, and if the server receives an invalid response from an upstream server, HTTP status code 502 is issued.
Service Unavailable – HTTP Status code 503
If a server is temporarily overloaded or unavailable.
