So, you finally decided to purchase proxies for your everyday needs. It's an initiative you expect to bring much success, whether you want to scrape data from websites, cop sneakers from online retailers, improve your privacy and security, or access restricted content.

However, even the most well-executed plans can hit a snag. A proxy server error may stifle your online progress despite following the manual proxy setup instructions to the letter.

What happens then? Should you throw in the towel? Absolutely not! There are several interventions you can use to fix proxy errors.

This article will help you understand what a proxy error is, the different classes of errors, their causes, and what you can do to resolve them. Keep reading below.

Before we explore proxy server problems, we must first answer several key questions: What is a proxy server? What is it used for?

If you are a regular internet user — aren't we all? — then you have probably heard about proxies. It is a tool that acts as a middleman between you and the internet.

When you send a request, the traffic flows from your device through the proxy to the destination server. The host then processes your request and sends the response to the proxy server, which routes it to your device.

This condensed approach can bail you out of several pickles as you use the internet.

For instance, residential proxies can help you evade geo-restrictions, expanding the range of content you can access. Similarly, you can use rotating data center proxies to scrape data from various platforms while avoiding detection.

That's just a fraction of the benefits you stand to gain when using a proxy server for your internet connection.

A proxy error can keep the merits we've discussed out of reach. However, you can troubleshoot and resolve such issues by following the instructions we'll outline later in this blog.

Before we get there, we must ask ourselves: What actually causes proxy server errors?

They occur when your proxy runs into a problem processing your request to access a particular online resource.

For example, say you want to use a proxy server to access an eCommerce shopping discount that is unavailable in your area. After doing some light research, it becomes apparent that residential proxies are the right way to go.

So, you purchase premium residential proxies from MarsProxies and set them up according to our detailed guide.

But alas, instead of a screen showing the discounts you desperately need, it's something else entirely—an HTTP error code manifesting as a three-digit number. Here's what you need to know:

In the example laid out above, the error code may stem from a variety of issues. Sometimes, the server can't handle the request, or it cannot accurately respond. In other cases, the problem may lie within your proxy server or the request.

Either way, the code's first digit will illuminate what it means and the steps you should take, if any. Officially, there are five categories of HTTP error codes, and you can tell them apart by the first digit, ranging from one through five. They are outlined below:

The first category of proxy status codes is represented by the number one. These are merely informational responses that indicate no problem has been detected.

In brief, they mean the host server has received your request and is working on it. As such, you do not need to take further action.

Here are a few examples:

This basically means the host server has received part of your request, and you can proceed with sending the rest.

If you decide to change the communication protocol during a browser transaction, this status code means the host has acknowledged the successful change.

A web server may need time to process complex requests, such as WebDAV. To prevent timeout errors on your side, it sends the 102 Processing status code, meaning it has received your request and is currently processing it.

If the HTTP status code on your screen is between 200 and 299, you can relax, as this indicates the upstream server has received and handled the request successfully.

Here are the 2xx status codes you will likely come across as you utilize proxy servers:

It means the request succeeded, and the host has returned the resource you requested.

Your request succeeded, and the host created a new resource as output. This is typically what you get after sending POST requests.

When you see this status code, the server has received your request but will process it later. Only then will you know the outcome.

As we mentioned earlier, the first two classes indicate the request you sent via your proxy server was successful. Now, it's time to get to the more complicated stuff: error codes that point to a problem on your side, the proxy server, or host server issues.

Should the error code on your screen begin with the number three, you must take extra steps to complete your request. This likely won't be a problem when using common browsers like Chrome or Safari, as the host will automatically redirect you to a different URL with the requested data.

However, taking the more complex and flexible route using scripts may be a bit more nuanced as you must deal with these codes yourself. You best be careful, though, as a slight mistake, and you may end up with a never-ending loop of redirects.

Here are common examples:

This status code signifies the target host server is redirecting you to multiple URLs with the resource you are searching for. It is now upon you to select one.

It means your request has been permanently redirected to a new URL. You won't see the original URL, as search engines will only index the new one, which is what you should use for future requests.

Suppose your request is redirected more than five times for a single URL. In that case, browsers like Chrome will display "Too many redirects."

This proxy error code is quite similar to 301 in that it indicates that a resource has moved, albeit, this time, temporarily.

Unlike the 301 status code, which requires you to stick to the new URL for future requests, the situation is quite different if the resource has only moved temporarily. Here, you can revert to the original URL for future requests.

Though rare, this error status code can sometimes pop up. It indicates that the resource you are after is only accessible via a proxy, whose URL is mentioned in the response.

Due to security concerns, most web browsers do not display this code. If you come across it, it's best to consider manually setting up custom residential proxies or datacenter proxies rather than relying on this status code for dynamic redirection.

On to the fourth tier of proxy server error codes. While the third class dealt with redirect issues, this is a different kettle of fish altogether.

4xx error codes mean the request you are sending has an error, and the target web server cannot process it. If you see such responses, you can take mitigatory measures like checking the syntax, headers, credentials, and format used to send the request.

Here are a few common examples of 4xx proxy server error codes:

If you see this error code on your screen, it means your device could not connect to the target proxy server because of invalid syntax, non-HTTP traffic, and mismatched protocols, among other reasons.

To solve this issue, examine the URL to ensure it is properly formatted. Also, verify that the HTTP headers do not contain any syntax errors. Should the issue persist, confirm that you have formatted the request body according to the upstream server's expectations.

The 401 unauthorized error code means the server has received your request, but it refuses to authorize it without the proper credentials.

In such a case, you should provide the required information. Depending on the exact situation, input the username and password of the proxy server you are using or an API key when accessing APIs.

Unlike the 401 Unauthorized error codes that suggest you could access the desired info with proper authentication, 403 Forbidden status means the server acknowledges your request but refuses to respond.

The reasons are multifaceted; however, typically, it means you do not have permission to access the desired resource either because the system is controlled by user roles or it is restricted in your region.

You must check the underlying permission control issues restricting access to resolve this error. For instance, confirm your account has the required permissions and that the proxies are adequately authenticated.

This response implies your request cannot find the desired resource on the server because the link is broken, the owner deleted the page, or you mistyped the URL.

In this case, confirm the current URL has no typos or consider sending the request to a different one altogether.

This error status code means the proxy server requires credentials. It may be because of incorrect authentication on your part or inaccurate credentials in your scraper.

To fix this proxy server error, update your proxy settings to include whitelisted IPs and the appropriate credentials. If you still get the "proxy server not working" message, contact your provider for assistance.

The server returns this error code when configured to wait for your request, but you have yet to send any. Fortunately, you can resend the request at any time.

However, if the issue persists, check your proxy settings and ensure you have a stable internet connection.

The host will return this error when you send too many requests from the same IP address within a short timeframe. As such, it considers you a bot and immediately restricts access.

It is worthwhile to note that some providers use the 429 code to rate limit access to specific websites.

The fifth class of proxy server error codes is denoted by the number five at the beginning. These responses indicate the proxy server is not connecting because of an inherent problem.

In such cases, the exact code will point to the proxy error. It could be software, hardware, configuration, gateway, overload, timeout, or unsupported feature issues.

If you encounter a 5xx server error, try rotating the proxies or changing the proxy server type altogether.

That being said, here are the different types of 5xx error codes:

This error message occurs when the proxy server receives an invalid response from the upstream server.

To resolve it, clear your cache and cookie files. If this fails to work, consider changing your DNS and try connecting without a proxy server.

Should you see this error message, the upstream server you are trying to access is unavailable at the moment. It may be because it is overloaded with requests or it is undergoing planned maintenance.

However, you can see this response when the host identifies your proxy server and subsequently blocks it. In that case, try rotating your IPs or using a different server.

This code implies the proxy server did not receive a timely response from the host. It may occur due to network errors, server overload, or misconfigured proxies.

To fix it, check your proxy settings and adjust the timeout configuration to give the proxy more time for the upstream server to respond. Also, verify that there are no connectivity issues between the upstream server and your proxy address.

The reality is that there isn't an omnibus approach to fixing proxy error codes because it largely depends on the specific situation, the website you are accessing, and the types of proxies you are using.

Don't give up just yet. According to experts, the following tips could potentially resolve such issues, allowing you to return to seamless browsing.

A proxy error may occur because of an unstable internet connection. There are tons of online diagnostic tools you can use to analyze your connection stability.

If there is a problem, check your modem and router to ensure your proxy server has robust access to the internet.

Incorrect proxy settings can cause various issues, leading to the error codes discussed above. While you may have to change the default settings, ensure the proxies you use are compatible with the target websites.

When dealing with proxy problems, remember the classic old troubleshooting saying: "Have you tried turning it off and on again?" Simply restarting your proxy server can fix glitches and other problems affecting proxy performance.

Old, outdated browsers may be incompatible with some proxy servers and websites, causing the proxy error codes discussed above. As such, it is important to check your browser's compatibility and ensure it is up to date.

Sometimes, the issue may be beyond your control. Luckily, premium proxy providers offer 24/7 customer support. Don't hesitate to reach out to the agents for assistance.

With this information, you are well-equipped to roll with the punches and easily resolve proxy server error codes.
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Remember, knowing the exact error code is important because it lets you know whether the issue is on your side, the proxy server's, or the upstream server's side. We hope our article helps you resolve proxy issues and fosters a streamlined browsing experience.