What does 401 error code mean? Detailed explanation of common causes and solutions

in the process of daily browsing a web or calling a network interface, many people have encountered the situation that the page cannot be loaded normally. 401 error code is one of the more common ones. Many users are often confused when facing this prompt, do not know where the problem is, and do not know how to solve it. This article will start with the basic definition of 401 error code, deeply analyze the common reasons for its triggering, and give targeted solutions in combination with actual scenarios to help you quickly troubleshoot and solve such network access problems.

What is the 401 error code?

to solve the problem, we must first clarify the problem itself. Let's start with the basic definition and expression of 401 error codes.

1, the official definition of 401 error code

401 error code is a type of HTTP status code, which belongs to the category of client side error status code and is officially defined as "unauthorized". When the client side sends a request to the server, the server detects that the request does not carry valid authentication information, or the authentication information carried is invalid, it will return a 401 error code to inform the user that authentication needs to be completed before accessing the target resource.

2, common forms of 401 error codes

in actual scenarios, 401 error codes are expressed in various forms. The browser usually displays the English prompt "401 Unauthorized", and some Chinese websites translate it as "Unauthorized Access" or "You do not have permission to access this page"; when calling the API interface, the JSON or XML data returned will clearly contain the status code identification of 401, and may also explain the reason for the verification failure.

2. Common reasons for triggering 401 error codes?

understand the definition of the 401 error code, let's sort out the common reasons for this error, and analyze it from the two dimensions of the client and the server.

1, client authentication information abnormality

this is the most common reason for triggering 401 error codes, including a variety of situations. For example, the user does not log in to access the page that requires permissions, or does not log in again after the login status expires; it may also be the wrong account password entered, or the API key, Token and other verification information filled in when calling the interface are wrong, which will cause the server to determine that the request is not authorized and return a 401 error code.

2, server-side authentication configuration issues

In addition to the problems of the user side, the configuration error of the server side can also cause 401 error codes. For example, the authentication rules of the server are misconfigured, and the resources that do not need to be verified are set to require authorized access; or the authentication service fails and cannot recognize the valid authentication information of the user normally; In addition, the server's permission allocation error, setting the user's access rights too low, will also cause the user request to be intercepted and return 401 error codes.

How to solve the 401 error code problem?

for the 401 error codes caused by the above different reasons, we can take corresponding solutions to troubleshoot from the client and server.

1, the user side of the investigation and solution

users can first troubleshoot problems from their own operations. The first step is to check whether you need to log in. If the target resource needs Orthrus, complete the account login operation in time; the second step is to confirm whether the login information is correct. If the account password is incorrect, re-enter the correct information to log in; the third step is to check whether the login status has expired. The login status of many websites has a time limit. After the expiration, you need to log in again to obtain valid verification information, so as to solve the 401 error code problem. In addition, when calling the interface, carefully check whether the API key, Token and other information are filled in correctly to avoid triggering 401 error codes due to information errors.

2, server-side troubleshooting and solutions

If it is a problem on the server side, it needs to be investigated by operation and maintenance or developers. First, check the authentication rule configuration to confirm whether there is an error in setting the public resource to require authorization, and adjust the configuration in time; secondly, check the running status of the verification service. If the verification service fails, restart the service or repair the fault in time; finally check the user permission allocation to ensure that the user has the corresponding permission to access the target resource to avoid 401 error codes due to insufficient permissions.

4. How to avoid encountering 401 error codes again?

solve the current 401 error code problem, we can also take some measures to reduce the probability of encountering such problems again in the future.

1, user-side preventive measures

users can develop good operating habits, access to resources that require permissions to confirm the login status before, to avoid continuing to operate after the login status expires; use a safe way to save the account password to avoid inputting invalid information due to memory errors; when calling the interface, the API key, Token and other verification information are properly stored, and the validity of the information is regularly checked to avoid triggering 401 error codes due to information expiration or errors.

2, server-side optimization measures

server side can start from the configuration and service optimization, improve the configuration logic of authentication rules, add clear error prompts to help users quickly understand the triggering causes of 401 error codes; regularly maintain verification services to ensure stable operation of services, avoid service failure caused by verification failure; establish a sound rights management system, reasonably allocate resource access rights according to user roles, and reduce 401 error codes caused by wrong rights configuration.

To sum up, 401 error codes are common HTTP unauthorized errors, which are triggered by user-side operation errors and server-side configuration failures. By clarifying the definition of 401 error codes, we can investigate the root cause of the problem from the user-side and the server-side respectively, and then take corresponding solutions to quickly restore access. At the same time, taking preventive measures can effectively reduce the probability of encountering 401 error codes in the future, and improve the smoothness of network access and interface calls.