Understand HTTP protocol status codes: Let you better understand the website access process

HTTP protocol is one of the most important protocols in the modern Internet. Whether browsing the web, sending emails, or watching online videos, almost all network services communicate based on the HTTP protocol. When accessing websites using the HTTP protocol, you will often encounter various status codes. Understanding these status codes is very important for us to better understand the website access process and troubleshoot problems. This article will introduce the common status codes of the HTTP protocol and their meanings.

There are five types of status codes in the HTTP protocol: informational status codes, success status codes, redirection status codes, client error status codes and server error status codes. Each status code is represented by three digits, making it easy to quickly understand the status through numbers.

First, let’s take a look at the informational status codes. An informational status code means that the server has received the request and is processing it, but further action is required to complete the request. For example, a 100 status code indicates that the server has received the request headers and the client should continue sending the request body. The 101 status code indicates that the server has understood the client's request and is switching protocols.

The success status code indicates that the server successfully processed the request. The most common status code is 200, which means the server successfully returned the requested data. This is the most common status code when we visit the website, indicating that the web page has been returned to us correctly. Other success status codes include 201 (Created, indicating that the request was successful and the server created a new resource), 204 (No content, indicating that the server successfully processed the request, but did not return any content), etc.

Redirect status code indicates that the requested resource has been redirected to another URL. The most common status codes are 301 and 302, which represent permanent redirection and temporary redirection respectively. When we access a web page, but the web page has been permanently moved to another URL, the server will return a 301 status code and bring the new URL in the response header, allowing the browser to re-initiate the request. The 302 status code represents a temporary redirect and is often used for temporary website maintenance or jumps.

Client error status code indicates that the request sent by the client has an error. The most common status code is 404, which means the requested resource does not exist. When we enter an incorrect URL into the browser or request a web page that does not exist, a 404 status code is usually returned. Other client error status codes include 400 (Bad request, the server cannot understand) and 403 (Access Forbidden, the server understands the request but refuses to execute it), etc.

The last is the server error status code, which indicates that an error occurred when the server processed the request. The most common status code is 500, which means an internal server error occurred. When the server program encounters an exception, encounters an error, or cannot handle the client's request, it will return a 500 status code. Other server error status codes include 502 (bad gateway), 503 (service unavailable), etc.

Understanding the HTTP protocol status code can help us better understand the website access process. When we visit a website, we can determine whether the request was successful, whether the resource exists, whether redirection is required, and whether a server error occurred by looking at the status code. If we encounter a problem, we can quickly locate the problem based on the relevant status code and provide effective clues for troubleshooting and troubleshooting.

In short, it is very important to understand the status code when using the HTTP protocol to access a website. By understanding the different status codes and their meanings, we can better understand the website access process and effectively troubleshoot and solve possible problems. I hope this article will help everyone understand the HTTP protocol status code.

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