501 Not Implemented Error: Main Causes and How to Fix It

4 min. read

A 501 Not Implemented Error is an HTTP error that indicates the method used to fulfill the request does not work or was not found on the server. Read on to learn its main causes and the best tips for how to fix it.

All kinds of errors lurk in the online world. Some errors you may be familiar with are the 404 Not Found Error and the 503 Service Unavailable Error that can negatively affect your SEO.

But many other less-known errors can appear on your site.

One of those errors is the 501 Not Implemented Error.

As the name suggests, it's up to no good.

And you would be right!

The Error 501 can be a nuisance for website owners as it's a server-side error. In other words, it can be more challenging to fix as something on the server-side of things is causing the issue.

Here's an overview of what it is, its main causes, and what you can do to fix it.

Let's jump right into it!

What Is a 501 Not Implemented Error?

A 501 Not Implemented Error is an HTTP error that indicates the method used to fulfill the request does not work or was not found on the server. In other words, the server doesn't recognize the request method and is not capable of supporting it for any resource.

This error belongs to the 5xx status codes group, which are errors that appear due to something wrong on the server-side of things, not the client. The request the client made is good, but the server cannot generate the requested resource.

To explain the process, here's an example:

You try to access your site that can be found at the following address:www.mywebsite.com.
A request is made to the web server using what is known as the HTTP protocol.
The server responds to you.
If the request is successful, the server will deliver the requested resource. If not, you'll be presented with a corresponding status code.

Since the Error 501 is a server-side error, you can’t fix it on your own, although you can try a few troubleshooting techniques. The recommended thing to do is contact your hosting provider if everything else fails.

How Can a 501 Not Implemented Error Appear?

The Error 501 message can appear in any operating system and any browser. Whether you're using macOS or Windows, Google Chrome, or Safari, the error can show up in certain situations.

Every browser displays the error message differently. The most common ways of how the error can be presented to users include:

501 Not Implemented
Error 501
HTTP 501
HTTP Error 501 Not Implemented

What Are the Causes of a 501 Not Implemented Error?

There are several causes for the 501 error, including, but not limited to:

Viruses or Malware

It's possible that your device got infected by a virus or is affected by some malware. The virus and malware may negatively affect the functioning of the system so that it's preventing the browser from establishing communication with the server.

The culprit in this scenario is your infected device and not the server.

Tip: Perform a complete scan of your system to check for any security threats that can lead to a communication failure.

Server Overload

Apart from viruses or malware, server overload can be another cause for the website crash. For example, your site may have experienced a surge in traffic that resulted in slowed down communication and eventually a failure of the server to fulfill the request. Surges in traffic generally are usually due to promotions, Black Friday sales, bot traffic, or an overly successful marketing campaign, among other things.

Tip: To avoid the scenario where your site crashes due to a surge in traffic, make sure you look for a hosting solution that will scale to your needs.

Expired Server Software

The Error 501 can also appear if the server is out of date. Although this is highly unlikely to happen as most providers keep their software up-to-date, it may happen with sketchy providers that offer cheap or free services.

Tip: If you have purchased services from an untrustworthy company just to save a few bucks, consider switching to a more reliable provider to avoid the worst-case scenarios from taking place.

Why Should You Fix It?

The biggest problem with the Error 501 is the customer experience.

Put yourself in your visitors' shoes. Imagine landing on a page, eager to read its contents or make a purchase, only to be welcomed with a message that says:

HTTP Error 501 Not Implemented.

This will frustrate your visitors to immediately leave the site and probably head over to your competitor's. Your brand will leave the impression of being untrustworthy and unprofessional. In the long run, you can lose many business opportunities vital for your business's survival.

The second issue with an HTTP 501 Error is that it negatively affects your SEO.

Google regularly crawls your website, going from one page to another to check for any changes to your site, dead links, errors, etc. The negative effects of the error grow as your site remains unavailable for an extended period.

If your site is down for 15 minutes, the Google crawler will get the page delivered from cache. Or, you may even get your site up and working even before Google gets a chance to scan it. You're saved!

However, if your site is down for 10 hours or more for example, then Google may think the 501 error is a site-level issue that needs to be addressed. As a result, it can penalize your site, causing your rankings to drop.

How Can You Resolve the 501 Not Implemented Error?

Before reaching out to your host for help, here are a few things you can try to resolve the issue:

Try Reloading the Page

The first and easiest thing you should do when faced with a 501 error— or any error for that matter— is to refresh the page.

Wait a few minutes and click the refresh button on the upper left side of the screen. The alternative is to click F5/Ctrl+R on your keyboard.

If the error disappears, congrats! It was just a temporary error between the servers.

But if the issue persists, continue with the second tip explained below.

Clear Your Browser's Cache

Browsers' function is to store data, so they don't have to load websites from scratch every time you access one of them. It's something known as caching.

Invalid login information may be stored locally in your browser that can be disrupting the log-in process.

Fixing this issue is relatively simple. Here are instructions on how to clear cache in different browsers:

Disable Proxy Server Settings

If the browser uses a proxy server, this may be another cause for the error. Check if the feature is enabled in your browser, and if it is, disable it.

If you need additional help disabling the proxy settings, check out the following resources:

Get in Touch With Your Host

Although some errors can be fixed with some troubleshooting from your end, the 501 error is almost always due to an issue with the server.

So, if you tried the three methods explained above and the error still appears, then it may be time to get in touch with your hosting provider.

Your hosting provider will have access to better diagnostic tools and can do a better job of detecting the problem.

Final Word

Knowing what the 501 Not Implemented Error means can help you quickly find a solution to the problem before the Google crawler scans your website or visitors try to enter a page.

To prevent this error from impacting your online rankings and losing valuable business opportunities, try the suggested solutions we've outlined in this post and avoid this scenario from happening again in the future.

We've even put together this comprehensive HTTP status code cheat sheet that you can use as a reference to learn about the different types of status codes and their meaning.

Last for not least, make sure you invest in proper website maintenance services to detect errors the moment they appear. Remember: Regular monitoring and maintenance will help keep you worry-free and your website error-free.