What is 401 Unauthorized Error & How to Fix it

When you browse the web, many times, you may run into issues while accessing the desired web pages and get the responses as different status codes. 

One of the most typical HTTP status codes that you may encounter is the 401 Unauthorized error. When you receive the 401 status code, it indicates that the request you sent to the website or web application cannot be authenticated. This means that the web page you are trying to access is not able to load because of the invalid user ID and password. 

Alternatively, we can state that the 401 Unauthorized error signifies that the server’s request did not validate because the login information for the target resource was invalid. 

The 401 error is a client-side error. Luckily, in many cases, it is pretty straightforward to resolve this error. Moreover, it is possible for each website to customize the 401 error to be displayed. As a result, there are different variations of this error, as follows: 

• HTTP Error 401
• 401 Authorization Required
• 401 Unauthorized Error
• Access Denied

In this blog post, I shall walk you through some of the most effective ways to fix the 401 Unauthorized error. Prior to it, let us understand a few common causes of this error. 

Causes of the 401 Status Code

Before delving into the ways to fix the 401 error, it is important to understand its causes. Here are a few common reasons for the 401 error to occur: 

• Entering the wrong URL of a web page you are trying to access. 
• Invalid username and password. 
• Outdated browser cache and cookies. 
• Plugin misconfiguration. 
• Limitations in the .htaccess file of the website.

For example, consider that you are trying to access a password-protected web page without logging in or entering the correct username and password. If this is the case, you will definitely encounter the 401 Unauthorized error. 

Many times, it may be a possibility that the 401 error might occur due to the web server. 

• The server might block the client from accessing the requested resource. 
• The authentication process of the server might have broken. 

How to Fix the 401 Unauthorized Error? 

Now that you know a few major causes of the 401 error. It is time to resolve this error. Here are a few typical ways to do so. 

Let us explore!

1. Check For Errors in the URL

The most common reason for the 401 error would be the incorrect URL you have entered, or the link that you click on directs to the wrong URL. 

Make sure to check the URL you enter in the browser’s address bar is correct and includes all the necessary characters and numbers. 

Also, when it comes to the hyperlink, cross-check if there are any typos. It may be a case where the hyperlink you click may be outdated or mistyped. In such a situation, visit the website’s homepage and navigate to the restricted web page manually. 

2. Reload Page 

Reloading is a typical solution to fixing various HTTP error codes, and 401 is no exception. Try reloading or refreshing the web page and see if it loads. You can do it by pressing the F5 button or using the Refresh or Reload button. 

3. Delete Your Browser’s Cache

A browser cache is a temporary storage of resources (web pages) in a browser. It improves the overall browsing experience, as it reduces the page loading time. A web cache stores a website’s static assets – data that remains the same even for repeated visits. 

The invalid login information may get stored in a browser’s cache, which may lead you to the 401 error. If this is the cause of the error, clearing your browser’s cache would be an ideal solution. 

When you clear all cache, the browser loads a new version of the page you are trying to access. Now, you can enter valid credentials and load the page. 

Read: How to Clear Cache in Chrome, Firefox and Edge Browser

4. Flush DNS 

Another solution to get rid of the 401 error is flushing your DNS (Domain Name System). Though the 401 error may rarely be caused due to DNS, flushing it will rectify the error. 

If you use a Windows system, you can flush DNS by entering the ipconfig/flushdns command in the command prompt and hitting Enter. 

5. Logging Out and Logging in Again 

One of the best ways to rectify the 401 error is to log out from the website and log in again with valid credentials. If the website is under maintenance and displays this error, this solution can do wonders. 

6. Contact the Website 

If you are done with all of the above ways and still cannot get rid of the 401 error, the last option is to contact the website administrator. By using the Contact Us page of the website, you can look at the website’s contact details and get in touch with them to report an error. 

7. Disable Password Protection

If you are a website owner or webmaster and don’t want your visitors to suffer from the 401 error, the best way is to disable password protection for the complex sections of the website. I understand this is not possible in most scenarios but at least you can debug things by doing this in your release/testing environment.

Variations of the 401 Unauthorized Error

If a website runs on the Microsoft IIS web server, it displays more information about the 401 error. This means that the server provides clients with the specific cause of the error. 

The following table highlights the different variations of the 401 error and their descriptions: 

Error Status Code	Description
401.1	Login failed
401.2	The login attempt failed because of the server configuration
401.3	An attempt to log in failed because of ACS (Access Control List)
401.4	Authorization failed due to a filter
401.5	Authorization failed due to ISAPI/CGI application
401.501	The client has generated too many requests or exceeded the request limit.
401.502	When the client with the same IP address sends the request to a single web server, reaching the dynamic IP Restriction Concurrent request rate limit.
401.503	The server’s deny list consists of the client’s IP address.
401.504	The server’s deny list contains the client’s hostname.

Recommended: How to Fix 400 Bad Request Error, How to Fix 404 Not Found Error and How to Fix 403 Forbidden Error

Wrapping it Up!

This was all about different ways to fix the 401 Unauthorized error. It occurs when the client’s request lacks valid credentials to access the target resource. Being a client-side error, it is pretty easy to fix the 401 error. Try all the aforementioned ways and see which one does wonders for you. 

If you have any queries, feel free to leave them in the comments section below.