What Is a 501 Not Implemented Error (and How to Fix It)

Plus troubleshooting tips for admins

A “501 Not Implemented” error occurs when a website you visit lacks the functionality to retrieve or show information that your web browser has requested. A 501 error is one of several HTTP status codes your browser might display.

Your browser will display server error responses (or HTTP status codes) with numbers ranging from 500–599. These error codes have different means and different solutions. This article will show you how to fix the “501 Not Implemented” error on several devices and operating systems.

501 Not Implemented: What Does It Mean?

When you visit a website, your browser sends a request to the site’s server. If everything goes right, the website supplies the requested data. This response could be text, images, files, and so on. If there’s a problem with the web server and it fails to handle your request, your browser will display the “501 Not Implemented” error.

What this error means is that the server lacks the functionality to fulfill or “implement” your browser’s request. Even more precisely, the server fails to recognize theHTTP request methodused by the browser.

Most of the time, a 501 error is caused by a problem with the website’s server. However, on rare occasions, problems with your web browser and network settings could also trigger the error. Whatever the cause, the troubleshooting tricks listed below could fix the issue.

1. Reload or Refresh the Page

The “501 Not Implemented” error is sometimes temporary, perhaps due to server overload or traffic surge. If the site administrator fixes the problem quickly, reloading the webpage may resolve the error. PressF5orCtrl+R(Command+Ron Mac) on your keyboard to refresh the affected webpage. Do that as many times as you can. Proceed to the next troubleshooting solution if the error persists after refreshing the page multiple times.

2. Check the Website’s Server Status

Site monitoring tools (likeDownDetectororIsItDownRightNow) provide real-time reports of server outages for websites and online services. Perform a server status check on the website displaying the “501 error” using the tools mentioned above.

If the tools report a server downtime or outage, you’ll need to wait for the website to come back online. Contact the website administrator if the error persists after several hours or days.

3. Try a Different Browser

Visiting the website in a different browser can help determine if the problem stems from your browser, device, or the website’s servers.

If other web browsers load the website properly, that rules out the possibility of a server-side error. In that case, clearing your browser’s cache might resolve the problem.

4. Clear Your Browser Cache

Cached web datais supposed to help your browser load web pages faster. However, your browser may encounter issues loading web pages if its cache data becomes corrupt or outdated.

If the 501 error response code is specific to a particular browser, clear the browser’s cache and reload the webpage. Follow the steps below to clear cached web data in Chrome, Firefox, Safari, and Microsoft Edge.

Open a new browser tab, pasteedge://settings/clearBrowserDatain the address bar, and pressEnterorReturnon the keyboard. CheckCached images and filesand selectClear now.

Open a new browser tab, pasteabout:preferences#privacyin the address bar, and pressEnter/Returnon the keyboard. SelectClear Datain the “Cookies and Site Data” section, check Cached Web Content and selectClear.

Open Safari, selectSafarion the menu bar, and selectPreferences. Head to thePrivacytab, selectManage Website Data, chooseRemove All, and selectRemoveon the confirmation.

5. Disable Proxy Server

Yourcomputer’s proxy settingsaffect how your web browser(s) load certain websites. If you’resurfing the web via a proxy server, disable it (temporarily) and check if that stops the 501 error code.

By default, many web browsers use your computer’s proxy settings. So, unless you set up a manual/custom proxy configuration in your browser, disabling proxy at the system level should do the trick.

In Windows, go toSettings>Network & internet>Proxyand any manual or automatic proxy setup on the page.

To disable proxy settings in macOS, head toSystem Preferences>Network>Advanced>Proxies, and uncheck all proxy or HTTP protocols. SelectOKto save the changes and reload the website in your browser.

On a Chromebook, go toSettings>Network>Wi-FiorEthernetand select the active network. Afterward, expand theProxydrop-down menu, and set the “Connection type” toDirect internet connection.

6. Perform a Virus Scan

Malware infection on your computer can affect information exchange between your computer and the website’s servers. Before performing a malware scan, try visiting the webpage on another computer. If other devices load the webpage, the 501 error on your computer could be due to malware infection.

If you’re using a Windows PC, openWindows Defender (or Windows Security)and run a full scan of all files and running programs. Leave your browser open while you run the malware scan. You can also use third-party apps to diagnose security threats andfix malware infections in Windows.

For non-Windows users, check out some antivirus options for Mac, freeantivirus programs for Linux, andantimalware solutions for Chromebook.

Troubleshooting Tips For Website Administrators

Expired server software or subscription could land your site visitors on an HTTP 501 error page, as will incorrectNGINX configurationin your server settings. If you own or manage the website displaying the 501 error, ensure your hosting bills are paid. Additionally, make sure your web application is up-to-date.

Failure to fix this error in time could negatively impact your site’s SEO ranking. Contact your hosting provider for assistance if you have no technical knowledge of troubleshooting server-related issues on the backend.

Sodiq has written thousands of tutorials, guides, and explainers over the past 4 years to help people solve problems with Android, iOS, Mac, and Windows devices. He also enjoys reviewing consumer tech products (smartphones, smart home devices, accessories, etc.) and binge-watching comedy series in his spare time.Read Sodiq’s Full Bio

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