Understand common HTTP status codes and their meanings

Understand common HTTP status codes and their meanings

HTTP (HyperText Transfer Protocol) is a protocol for data transmission on the Internet. When using HTTP, the client sends a request to the server, and the server returns the corresponding HTTP status code after processing the request. Through the HTTP status code, the client can understand the server's processing results of the request.

HTTP status code consists of three digits and is divided into five categories:

1xx: Information status code, indicating that the request has been received and requires further processing.
2xx: Success status code, indicating that the request has been successfully processed.
3xx: Redirect status code, indicating that further operations are required to complete the request.
4xx: Client error status code, indicating that the server cannot process the request.
5xx: Server error status code, indicating that an error occurred when the server processed the request.

Here are some common HTTP status codes and their meanings:

1xx Status Code:

100 Continue: The server has received the initial part of the request and the client should continue ask.
101 Switching Protocols: The server has understood the client's request and will satisfy the request through the protocol switching policy.

2xx status code:

200 OK: The request was successful.
201 Created: The request has been completed and a new resource has been created.
202 Accepted: The request has been accepted for background processing, but the processing has not been completed.
204 No Content: The server successfully processed the request but did not return any content.

3xx status code:

301 Moved Permanently: The requested resource has been permanently moved to a new location.
302 Found: The requested resource temporarily responded to the request from a different URI.
304 Not Modified: If the client sends a conditional request and the request is already up to date, the server returns this status code.

4xx status code:

400 Bad Request: The server cannot understand the format of the request.
401 Unauthorized: The request is unauthorized, which means that authentication information needs to be provided.
403 Forbidden: The server rejects the request, which means the client does not have access rights.
404 Not Found: The server cannot find the requested resource.

5xx status code:

500 Internal Server Error: The server has an internal error and cannot complete the request.
502 Bad Gateway: A server working as a gateway or proxy received an invalid response.
503 Service Unavailable: The server is temporarily unable to process the request.

By understanding common HTTP status codes and their meanings, we can better understand the problems encountered when using the HTTP protocol. When we encounter an error, we can determine the specific problem based on the status code and take appropriate solutions. At the same time, the server returning the correct status code also helps the client handle the response correctly and improves the stability and performance of the system.

To summarize, understanding common HTTP status codes and their meanings is important for developing and deploying web applications. By correctly using and handling HTTP status codes, we can better troubleshoot and handle errors, and provide better user experience and service quality.

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