What is 401 Error? Learn How to Fix the 401 Error Code

My sixth sense is telling me that you are encountering a 401 error code on your screen. Am I right? Well, it usually means you are trying to access something online without the right login details. You can think of it like using the wrong key to open a locked door.

Although it is not as common as error code 233011 and 224003, it is still important to understand Error Code 401 for both visitors and site owners. In this guide, we will understand the 401 error meaning, its main causes, and learn how to fix or avoid the issue.

How to Fix the 401 Error Code? (Quick Summary)

Fix 1: Check if the URL is Correct
Fix 2: Verify Your Login Details
Fix 3: Clear Your Browser’s Cache and  Cookies
Fix 4: Flush Your DNS Cache
Fix 5: Remove Password Protection from Pages
Fix 6: Turn Off Plugins, Themes, and Modules

What is a 401 Error?

HTTP 401 Error (also known as 401 Unauthorized) shows up when a website or app blocks your access because you are not logged in properly. 

In technical terms, a 401 status code means your request is missing valid login details, like a username and password, API key, or access token. Without valid information, the server can’t verify who you are.

This error is part of the 4xx family of HTTP status codes, which deal with client-side issues. So, a 403 Forbidden and 404 Not Found error are different from this one. Each error code is trying to say something different to you:

• 401: I don’t know who you are.
• 403: I know you, but you are not allowed in.
• 404: I don’t even have what you are looking for.

Understanding error 401 helps you figure out why you can’t access a page and what steps you might need to take to fix it.

What are the Common Causes of HTTP 401 Errors?

Now that you know the 401 error meaning, you should also be aware of the most common reasons behind the issue:

1. Wrong or Outdated URLs: Typos in the web address can lead to a 401 HTTP error. Even if the link looks correct, the page might have been moved or deleted. In both cases, the server denies access because it sees the request as invalid or unauthorized.

2. Expired Cookies or Cache: Your browser uses cookies and cache to remember your login status. If this data gets deleted or expires, the server might no longer recognize you and block access.

3. Restricted URLs: Some web pages or files are locked behind server-level permissions. If you are not an authorized user, you will not be able to open those links.

4. Plugin or Firewall Settings: Security plugins and firewalls on WordPress sites can sometimes block access. This can happen even for admin users if they detect something unusual. 

5. .htaccess File Rules: If your site has a ‘.htaccess’ file with password protection on access rules, anyone without proper credentials will see a 401 error.

Apart from these, invalid or expired API tokens and misconfigured server settings can also trigger errors and block your access.

How to Fix a 401 Error Code? 

A 401 response code usually appears on your side, not the website. That’s why, in most cases, fixing it is simple. Here are a few steps you can try:

Fix 1: Check if the URL is Correct

As discussed above, one of the most common reasons for this error is a wrong or outdated link. So, the first measure is to double-check the web address you entered, especially if it has numbers, symbols, or extra slashes.

If you clicked a link from another site and landed on the error page, try visiting the website’s homepage and navigating from there. Or, search for the page again on Google to find the correct link. Even small mistakes in the URL can lead to this error.

Fix 2: Verify Your Login Details

As you already know, a 401 code error usually means your login information is incorrect or missing. So, make sure that you are signed in with the right username and password. Also, ensure that you did not mistype anything.

If unsure, you can just reset your password and try again. For password-protected WordPress sites, ensure you know how to reset the admin password if needed.

Fix 3: Clear Your Browser’s Cache and  Cookies

Browser saves login information and website data to make things load faster. But sometimes, old or expired data can cause login problems. Here’s what to do:

• Clear cookies and cache for the website that is showing the error.

  

• Reload the page and try signing in again.

Each browser has a slightly different way to do this, but you will usually find the option under ‘Settings’ > ‘Privacy’ or ‘Browsing Data’. 

Once cleared, the browser can load fresh data and may fix the error right away. Keep in mind that clearing this data may log you out of other websites too.

Fix 4: Flush Your DNS Cache

If the response code 401 still shows up, your device might be storing outdated DNS data. Clearing or flushing your DNS can help you fix this issue.

On Windows:

• Click on the Start menu, type cmd, and open Command Prompt.
• Now, type: ipcongid/flushdns.

  

• Finally, just press Enter.

On Mac:

• Go to Applications > Others.
• Now, open the Terminal app.

  

• Here, type: sudo killall -HUP mDNSResponder.

  

• Press Enter and enter your Mac password if prompted.

After the process is complete, refresh the page and check if the error is gone.

Fix 5: Remove Password Protection from Pages

Now, the last two fixes focus on the server-side issues. If your website shows a 401 Unauthorized error, it might be due to password protection on certain pages. You can fix this by removing it, only if you are comfortable working with website files.

Here’s how to do it safely:

• Open your hosting account’s File manager.
• Go to the folder that is password-protected.
• Now, look for a file named ‘.htaccess’, back it up first, and then delete it. Also, find the hidden ‘.htpasswd’ file, back it up, and then remove it as well.

  

Fix 6: Turn Off Plugins, Themes, and Modules

Sometimes, installed plugins or themes can also cause errors, especially on WordPress or similar CMS platforms.  So, if you can access your website’s dashboard:

• Go to Appearance > Themes and switch to the default theme.
• Visit Plugins > Installed Plugins, select all, choose Deactivate, and click on Apply.

  

If you can’t access the dashboard:

• Open the File Manager from your hosting account.
• Rename the ‘plugins’ folder under ‘wp-content’ to something else. This will disable all plugins at once.

  

• To change the theme manually, you might need to edit your database using phpMyAdmin.

Once the plugins and themes are disabled, you will be able to access the website. However, if you are still getting the error, I would recommend that you check with your website admin or developer. Or, you can contact your hosting provider for further assistance.

How to Recognize 401 Errors?

Now you know about the error, its main causes, and a few simple fixes to resolve it. We all know that it shows up when a website blocks your access. You will see a message saying that you are not allowed in. 

But how would you recognize that this has been triggered by a 401 error? Here are some common messages that can confirm this:

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

No matter the exact wording, all of these messages mean the same thing. You need proper login details to access the page.

Understanding the Variations of 401 Authentication Error

This error comes in different forms, each giving a clue about why your login request failed. Here’s a breakdown of the common 401 error variations and their meaning:

• 401.1 (Invalid Credentials): This means the login failed because the username or password was incorrect.

• 401.2 (Server Configuration Error): The login attempt failed due to issues with the server settings.

• 401.3 (Access Denied by Permissions): The resource is protected by an Access Control List (ACL), and your user account does not have the right permissions.

• 401.501 (Too Many Requests): The client has sent more requests than allowed, which can trigger the error.

• 401.502 (IP Rate Limit Reached): A specific IP address is sending too many requests in a short period, breaching the server’s dynamic request limits.

• 401.503 (IP Blocked by Server): The client’s IP address is blocked by the server’s security settings.

• 401.504 (Hostname Blocked by Server): The client’s hostname has been denied access by the server’s rules.

How to Avoid Error Code 401 in the Future?

I know fixing the HTTP error can be frustrating, but here’s how you can stop it from happening again:

• Make sure your website or app uses secure login systems like OAuth 2.0. This helps verify users properly and keeps unwanted access out.

• Regularly update authentication systems and run quick tests to catch issues early, before your users face them.

• Track authentication logs regularly to spot unusual login patterns early. This can help prevent bigger problems later.

• Teach users to follow smart security habits, like using strong passwords, enabling two-factor authentication, and being alert to phishing attempts.

Furthermore, always try to keep your browser updated. By following these steps, you can reduce the chance of running into 401 and other frustrating login errors.

Conclusion

That’s all I have, and what you need to know about 401 errors to resolve it. Knowing what causes such errors and how to handle them helps you get back online quickly and keeps your website secure. Just follow the basic steps mentioned in the guide, and you can avoid most access issues with ease.