When a client makes a HTTP request to a web server, the server responds a 3-digit number indicating the fulfillment status. The HTTP status code is included in the response header sent by the server to indicate whether the request has been successfully completed, has encountered an error, or needs further action from the client.

The status codes are grouped into five classes:

• 1xx (Informational): The request was received, and the server is continuing to process it.
• 2xx (Successful): The request was successfully received, understood, and accepted.
• 3xx (Redirection): Further action needs to be taken to complete the request. The client may need to redirect to another location.
• 4xx (Client Error): The request contains bad syntax or cannot be fulfilled by the server. The client seems to have made an error.
• 5xx (Server Error): The server failed to fulfill a valid request. It indicates an error on the server's part.

Examples

Some of the common status codeds returned by the web server include the following:

• 100 Continue: The client should continue with its request.
• 200 OK: The standard response for successful HTTP requests.
• 301 Moved Permanently: The requested resource has been permanently moved to a new location.
• 404 Not Found: The server cannot find the requested resource.
• 500 Internal Server Error: A generic error message returned when an unexpected condition was encountered on the server.

The HTTP status codes provide a quick way to understand the outcome of an HTTP request and can be useful for troubleshooting web applications. When you encounter a web page error, the accompanying HTTP status code can give you insights into what went wrong. Web browsers, web servers, and other software that communicate over HTTP use these status codes to convey information about the outcome of a request.

To learn more about HTTP status codes, please visit our HTTP Status Codes wiki page.