What is Error 502 Bad Gateway? How to Fix it?

Encountering the 'Error 502 Bad Gateway' is a common issue while working on websites, yet many people are unaware of what it signifies or how to resolve it. This blog post is designed to demystify this error, offering insights into its causes, solutions for fixing it, and strategies to prevent its occurrence in the future. Let's dive into understanding the 'Error 502 Bad Gateway,' its implications for your website, and the steps you can take to address and prevent it.

Updated: 01 Feb, 24 by Antoniy Yushkevych 12 Min

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As we know, this kind of error must have been witnessed while surfing the internet, and you are curious about what Error 502 Bad Gateway means. Why did this happen? While reviewing how to fix this, what to do now? Well, that is why you are here. During this blog post, We will help you with all this information. 
 
502 errors are called 502 bad gateways in technical terms. It can be caused due to multiple reasons, the website itself could be the faulty reason or main reason behind it, but sometimes there is a problem with your computer itself. We will look into solving this error later in the article. There are types of 502 errors as well; for instance, if you work with WordPress and this error arises, solving this can be very frustrating. If you are unaware of this kind of error, it might take away your motivation to work, but we have almost every answer to solve 502 errors. 

Technically, 502 bad gateway means a server received an invalid response from the upstream server while serving as a gateway or proxy. A gateway server means a server responsible for passing information and data between two networks or servers. Gateway also converts the protocol or format while transferring it. 

Too technical to understand? Here is the meaning in simple words.

In other words, 502 bad gateway means that the server you have been working on received an invalid response from another server because your server was acting as a gateway for another server. This error is a way to show that something is faulty in between server communications. 

For a more detailed explanation, you need to know that your browser sends a request to the respective web server every time you use a website. Just like any basic function of input-process-output, the web server receives and processes the request and then sends back the requested code/ information that the browser asked for. This requested information comes with an HTTP header and HTTP status code. 

This HTTP status code is not required until everything runs smoothly, but if the browser did receive an HTTP status code, that means something went wrong. Sending an HTTP status code is the server's way of informing you that there is a fault, and your website will show the error. That means that the request was accepted but not fulfilled.

Since the error code is generic, we cannot figure out what specifically went wrong. There are so many 500 status error codes. This brings us to an overview of the types of 502 errors.

Variation in 502 Bad Gateway error does not mean types of 502 errors but different names for the same error condition. Below is a list of how your website might show the error. 

  • “Error 502”
  • “502 Bad Gateway”
  • “502 Proxy Error”
  • "502 Service Temporarily Overloaded."
  • “HTTP Error 502- Bad Gateway”
  • “HTTP 502”
  • " 502 Server Error: The server encountered a temporary error and could not complete your request."
  • “502 Bad Gateway NGINX”
  • A blank white screen
  • Temporary Error (502)
  • 502. That’s an error
  • 502 bad gateway Cloudflare
  • Bad Gateway: The proxy server received an invalid response from an upstream server.
  • “502- Web server received an invalid response while acting as a gateway or proxy server. There is a problem with the page you are looking for, which cannot be displayed. When the Web server (while acting as a gateway or proxy) contacted the upstream content server, it received an invalid response from the content server.”

Websites like Twitter, Google, and WordPress have their way of displaying this error.

Twitter simply says- "Twitter is over capacity."

Here is what Google says when it faces 502 errors: 502. That’s an error. The server encountered a temporary error and could not complete your request. Please try again in 30 seconds. That’s all we know.”

WordPress simply says- 502 Error.

Cloudflare just says- Error 502 with an illustration that explains the problem is in the host server.

There can be numerous reasons for the error to happen; some of these reasons are listed below:

  • The website is too overloaded, which means there are too many users visiting the same website at the same time.
  • There might be some problem with your computer or browser.
  • The domain name is not resolvable. 
  • Origin server is down. The origin server might be too busy, or there might be a connection lost between the servers.
  • The firewall blocks the request sometimes. The firewall tends to block communication between the edge server and the origin server sometimes.

Whatever the cause could be, we have every possible solution for you.

These solutions depend on whether the problem is from your side or the origin server. If the problem is from the origin server, then there is not much you can do, but we should try our best to tackle it. 

1. Reload or Refresh the page

This is a classic solution to any error we face on any website. It has been proven effective in solving the problem for most of the part. This is also the easiest way to solve the problem. 

This is also the first thing you should do when encountering this problem. If the website does not load right after, wait a minute or two and then try again to reload the page. The shortcut for reloading is Ctrl+F5 or F5. 

The chances of this method working are 50- 50 as sometimes the error that occurred is temporary, and waiting for a few minutes can simply solve the problem by refreshing the page. But sometimes, as we discussed, the error is from the origin server, and just refreshing the page might not work, but it is worth a try. 

2. Check if the Site is Down for you or everyone.

Whenever you encounter a 502 bad Gateway error, you can check if your server is down or if it's the origin server problem. This can be checked by simply copying your website URL to some websites that check if the website is down overall. Some such websites are isitdownrightnow.com and downforeveryoneorjustme.com. 

This method will let you know where the problem is and help you solve the problem accordingly. For example, if the site is down for everyone, there is not much you can do. You will just have to wait, and you might use that time for something else. 

3. Try another Browser

As we discussed, the problem might be in our browser, and hence while the origin server is taking time to resolve the problem, you might try to visit the same website on another Browser. You should also try to avoid opening up too many browser windows simultaneously. That would increase the traffic on the browser, and therefore, your browser might run slowly. 

This method also helps you troubleshoot the problem of finding out where the problem is; if the website works in another browser, that means your browser was problematic. 

If the website still doesn't work with another browser, you know that it's not your problem, and you can move further to other solutions.

4. Clear Your Browser’s Cache

This might be one of the reasons why your browser is not working. You do not clear your browser's cache for too long, and the browser gets outdated or corrupt files that might be causing the 502 error to accumulate. 

Clearing your browser's cache from time to time is also healthy for your browser and helps it run smoothly, and may lead you to fewer encounters with 502 bad Gateway errors. 

For Chrome, you must press Ctrl+ H to go to the history page, select the desired cache and websites, and click on delete. For other browsers, you can find the guide easily online. 

5. Start your browser in Safe Mode.

A safe mode for your browser means using it with or without extensions and add-ons. If your safe mode is activated, the browser will delete your cookies and cache history at the end of the session. 

When you have successfully disabled all the extensions, reload the page and see whether the error appears or not. If the error got solved, that means one of the extension sites was causing trouble.  

Another reason for the error could be plugins. After you have disabled all your extensions and the error still appears, the plugin might be causing the issue. Enable your plugins one by one to find the culprit. 

6. Restart the device

When you have checked everything from your side, and you know that the site is only down for you and your browser is acting up, then that means your device might be facing some temporary problems, and a simple restart of the device might help you to troubleshoot those problems. 

7. Change DNS Servers

A problem in your DNS server might be the reason for 502 errors appearing on websites. A DNS server change is found to be effective. Your DNS server might not be responding because it was too crowded due to all the cache collected.

Simply flushing your DNS cache would help you resolve many problems. It is just like deleting any other history from your device. The guide to flushing the DNS cache can be found online easily. 

Changing your DNS server to a third-party server might also be proven effective. It could also help you improve your networks overall, such as by increasing speed or reliability. 

8. Fix Faulty firewall configuration

A faulty firewall configuration will block your request from reaching the original host server, and the server and the project will result in a 502 Bad Gateway error. Check your firewall configuration and fix the issues. 

A firewall causes the error because Firewall is responsible for protecting your websites or browser from viruses and malicious visitors. 

9. Temporarily disable CDN or Firewall

CDN stands for content delivery network. CDN can be a reason for the 502 bad Gateway error. You are using a third-party CDN provider. 

If changing the Firewall and CDN configuration does not work, try temporarily disabling them and reloading the website. This method is not 100% effective, but it is worth trying to see the problem. 

10. Contact your host

This is the final method to try when you have tried everything and nothing works out, which means the problem is from the host server. Try contacting or reaching out to your host service and ask them to fix the bug for you.

Please call or tag them on their official Twitter pages to let them know there is a bug in their server. Since they have an official team to troubleshoot any problems you face, it would be easier for them to solve them. 

When you have 10 solutions to one problem, one of them is likely to work for you. There is also a slight chance that these methods might not work because the reason for the error to appear is completely different from what we predicted. 

Your position as a user also affects the problem, such as there are different ways to solve the error 502 bad gateway if you are a web developer from when you are a visitor. If the first 9 methods do not work out, we are sure about the 10th method to approach your host. This is the last option on how to solve the HTTP 502 errors; most of the time, the problem of the small one can be solved from the users' side. If the problem is from your side and you can solve it, then it will save you a lot of hassle of the league approaching the host companies and asking them to solve a problem just for you. If you want to build your website with WordPress, then we recommend you buy this WordPress hosting.

Error 502 Bad Gateway

 

People are also reading:

A 502 error occurs when a server gets an invalid response from another server, while a 504 error happens when a server didn't get a response in time from another server.

Typically, it's a network or server issue, not directly related to security, but consistent errors should be investigated.

Misconfigured CDNs can cause 502 errors by disrupting the flow of information between the server and the client.

Yes, if frequent or prolonged, they can negatively impact search rankings due to poor site availability.

Yes, there are monitoring tools available that can notify you of 502 errors as they happen.

Different servers may have unique error messages or troubleshooting steps for 502 errors, but the basic issue remains the same.

Overlooking server logs, ignoring CDN or firewall configurations, and not checking for wider network issues.

Implement custom error pages that inform users of the issue and estimated resolution time.

Rarely. If a specific site consistently shows 502 errors, disabling extensions to test can help identify the cause.

Antoniy Yushkevych

Antoniy Yushkevych

Master of word when it comes to technology, internet and privacy. I'm also your usual guy that always aims for the best result and takes a skateboard to work. If you need me, you will find me at the office's Counter-Strike championships on Fridays or at a.yushkevych@monovm.com