401 Error: What are the common causes and how to fix it

When surfing the Internet, encountering a 401 error page can be troublesome, especially when the website contains the information you need. As the website owner or developer, this may leave a negative impression to your prospective visitors, preventing them from visiting or accessing your website in the future.

So, what’s causing this issue to recur every now and then and how should you fix it? This article will give you a quick overview of the 401 error and its common causes, including basic tips and procedures on how to fix it.

What is a 401 Error Code?

401 Error Code is an HTTP status code that refers to a client-side error caused by unauthorized access when visiting a password-protected website. This error can occur with any browser when a visitor fails to provide valid authentication credentials (e.g., incorrect URLs, outdated browser cache or cookies, plugin misconfiguration, etc.).

As a result, a variation of 401 error messages may appear on the screen depending on the browser the visitor is using.

401 Error variations

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

Google Chrome users and Microsoft Edge users are likely to see the “HTTP Error 401” error message below the phrase “If the problem continues, contact the site owner.”

Types of 401 Error

• 401.1 – failed login attempt.
• 401.2 – the server configuration caused the failed login attempt.
• 401.3 – the ACL (Access Control List) caused the failed login attempt.
• 401.501 – the client generated too many requests and reached the maximum request limit.
• 401.502 – error occurs when a client of the same IP reaches the dynamic IP Restriction Concurrent request rate limit by sending multiple requests to a single web server.
• 401.503 – the client’s IP address is in the server’s deny list.
• 401.504 – the client’s hostname is in the server’s deny list. 

Common causes of a 401 Error

Unlike what everybody thinks, a 401 error is quite common and should not be something a website user should worry too much about as long as they input valid credentials on their browser’s address bar. However, it’s also good to know the common causes of this error to prevent or resolve them in the future.

Some of these causes include:

Incorrect uRL

A minor mistake such as typing an incorrect URL is a common cause for a 401 unauthorized error to appear on your screen.

Outdated browser cache or cookies

At times, your browser’s cache data and cookies are the main culprit for this type of error, especially when they expire, preventing your browser’s request from successfully going through.

Plugin misconfiguration

In some cases, a 401 error happens due to a plugin error or incompatibility which causes your firewall to mistake your login attempt as a malicious activity.

Server protected uRLs

Many hosting providers intentionally set password protection on their servers to prevent general access to their website’s restricted resources. This results in a 401 error page to pop up on your end.

Restricted .htaccess file

Finally, when a website owner forgets to remove their previously set password protection, the apache directives from their site’s .htaccess file will automatically be added, causing the 401 error code to display on the screen.

Error 401 vs Error 403

When accessing or visiting a website, the WWW-authenticate header reviews the authentication method applied for granting you access to a web page. If it detects any missing valid authentication credentials, the error 401 error code will automatically display, indicating an unauthorized or expired session from your end.

On the other hand, error 403, or mostly known as the “403 Forbidden” error code, is a response status code indicating a denied access from the server despite acknowledging a requested resource access from you. This type of error is somewhat the same as 401 error. However, any re-authentication credentials your provided won’t change the web page access due to the website owner’s restrictions.

Error 401 vs Error 404

Compared to the 401 error code, error 404 indicates a Not Found response status code. If a website is showing this error message, it typically indicates that there is a broken or dead link. This means that the resource needed to access or run the website is either temporarily or permanently unavailable.

This error may be due to moved or deleted pages, mistyped URL, caching issues, DNS settings problems, or missing assets from the website. Whatever it may be, whether this error is caused or located within the hosting service or the domain name system, error 404 won’t allow you to access the website.

Read also: Understanding 404 Errors: Causes and Fixes

How can I fix a 401 Error on my website?

Encountering a 401 error page can be frustrating but is fixable now that you know the problem is coming from your browser. Below are a few examples of how you can resolve this issue.

Inspect and correct URL errors

Manually typing long URLs increases the chances of making errors. Take note that website owners may update, move, or delete their web pages at any time. If you encounter the 401 server error or get redirected to another website, double-check for any wrong URLs from your browser’s address bar and correct them.

Clear browsing data, cache, and cookies

The purpose of browsing data, cached images, and cookies is to improve your online experience by limiting page loading time. However, when they become outdated, they cause unwanted interruptions to your authentication process. By cleaning invalid data from your device’s internal storage, you help your device run optimally and prevent the 401 error message from displaying on your screen.

To clean your browsing data on Google Chrome, you can follow these steps:

1. Go to your browser’s settings by clicking the menu icon on the top-right corner of your browser, then click Settings. 
2. Under the Privacy and Security option, select Clear Browsing Data.
3. From the drop-down menu on the Basic tab, you may set the time range to either Last hour, Last 24 hours, Last 7 days, Last 4 weeks or All time.

Depending on your preferences, you may opt to clear only your browsing history, cookies and other site data, cached images and files, or all of them.

For Mozilla Firefox users, clearing your browsing data may look slightly different compared to Chrome, which is done by clicking the library icon on the top-right corner of your browser. From there, click Clear Recent History, then choose a time range. If you consider the Everything option, all your browsing & downloading history, active logins, search history, cookies and cache will be removed from your device’s internal storage.

Clear DNS Cache from your device

If the same error occurs after clearing your browsing data, the next thing you should do is to clear your DNS resolver cache. Although this step is not as common, you can do this by opening your command prompt (Windows) or Terminal app (Mac).

For Windows users:

1. Press the Windows key on your keyboard or click on the Start menu.
2. Type “cmd” on your search bar, and press Enter.
3. On the command prompt window, type the command “ipconfig/flushdns”.
4. Press Enter.

For Mac users: 

1. Head to your Finder.
2. Click Applications, then Utilities.
3. Double-click on the Terminal app to open it.
4. In the Terminal window, type the following command: “sudo killall -HUP mDNSResponder”. 
5. Press Enter.
6. Refresh your website to check if the 401 error has been corrected.

Remove security plugins from your website

From the developer’s perspective, if your visitors are still having trouble accessing your website, try deactivating your site’s security plugins or WordPress plugins.

If you’re using a WordPress site, open your WordPress dashboard, choose the Plugins option, and click Installed Plugins. Then, select the security plugin you wish to deactivate from the drop-down menu and test whether the 401 error message has been resolved. Once fixed, your visitors may now have server access to explore your website.

Review the security settings of your website

As a website developer, another way to resolve your site’s 401 error issue and approve a client request to access your web page, you can disable password protection. You can do this by following these steps:

1. Start by opening your hosting panel through Site Tools.
2. Open the Security section.
3. Select the Protected URLs option. 
4. Click Manage Protected URLs.
5. Delete any protection settings not needed under the Actions column.

Check the .htaccess file of your website

Lastly, if any of the methods mentioned above doesn’t resolve the 401 error, inspect your site’s .htaccess file since password protection is not limited to your hosting panel. To proceed with this method, go to your File Manager (FTP), check your .htaccess file, and then edit its code.

Best practices to avoid 401 Errors

Overall, the best way to avoid those pesky 401 errors from popping up on your screen every now and then is to simply input the proper authentication credentials, which includes the correct username, user ID, and URL.

At the same time, regularly clearing your browsing site data, cache data, and cookies beforehand is also helpful in increasing your user experience. It reduces specific problems such as slow page loading speed and other formatting issues.

Browse your preferred site with ease

A 401 error is often temporary and fixable, and it isn’t serious enough to worry about. However, it can be very bothersome to deal with when it happens too many times. By following the helpful tips above, you can quickly resolve 401 errors and enjoy a smoother browsing experience.