The 502 Bad Gateway Error indicates that the internet server has returned an invalid response when trying to access a web page.

However, this error might also arise as a result of computer issues.

Aren’t you sure what the 502 bad gateway means or how to solve it?

Here’s a step-by-step guide to resolving the 502 Bad Gateway Error. Learn what it means, how to identify it, and how to solve it.

What is a 502 Bad Gateway Error?

When you try to open a web page, your computer sends a request to a webserver to access that page. When the server gets your message, it completes your request and returns the content with an HTTP header and HTTP status code. The communication between your system and the web server may experience multiple problems as a result of this.

The 500-range HTTP status codes like 500, 501, 503, 504, and so on indicate server errors among those networking faults.

502 error

The 502 error is one of the status codes, which indicates that the web server you’ve connected to is serving as a proxy for data relayed from another server, but that server has returned an invalid response.

Depending on the operating system, browser, web server, and host, the 502 Bad Gateway Error can appear in various ways. The following are the most frequent forms of the temporary HTTP error 502 Bad Gateway:

  • HTTP Error 502 Bad Gateway
  • 502 Proxy Error
  • 502 Bad Gateway NGINX
  • Server Error
  • Gateway 502 Service Temporarily Overloaded
  • HTTP 502
  • Temporary Error 502

502niginx

Here’s an example of how Google displays it.

google-502

Other services, such as Twitter, may display a completely different message in response to a 502 Bad Gateway error, such as “Twitter is over capacity.” This appears to be a bit more user-friendly.

502twitter

Causes of 502 Error Bad Gateway

Let’s examine what causes a 502 bad error before we look at how to resolve it. The 502 gateway error is a temporary error that can occur for a variety of reasons. The following are some of the most common causes.

  • Due to the sudden spike in traffic (Server overload)
  • When the firewall blocks the request
  • When the domain address is not resolvable
  • Server software timeouts (Returning a request from a web server takes longer than intended.)
  • Some browser extensions can also sometimes lead to errors, mainly an AdBlock extension.

How To Fix The 502 Error?

A 502 bad gateway error usually indicates a network/server issue; sometimes, it can also be a client-side issue. These options vary depending on whether the problem is at our end or the origin servers. If the origin server causes the issue, there isn’t much you can do as a user, but we should check and confirm that the problem isn’t at our end.

If you are a user, try these:

Try reloading the page.

When you get a 502 bad gateway problem, one of the first things you should do is wait for a few minutes and then reload the website. This is because a temporarily overloaded server could have caused the problem.

Check whether the site is down for others.

If you’re experiencing problems connecting to a website (for whatever reason), you can see if it’s just you or if other people are also having the same issues. There are numerous tools available for this, like down.com.

checkstatus

This method will show you where the problem is and will assist you in resolving it. If the site is down for everyone, there isn’t much you can do. You’ll just have to wait until it is resolved.

Try Another Browser

The 502 Bad Gateway error may also be caused by a problem with your browser. Using a different browser to see if it works is an easy method to test this. Google Chrome, Mozilla Firefox, Apple Safari, or Microsoft Edge are all options. If the error appears in the new browser as well, you will know it’s not a browser problem, and you should try a different solution.

Clear Browser Cache

If switching to a different browser solves the problem, your main browser may have cached outdated or corrupt files that are creating the 502 error. Attempting to open the website after removing these cached files may resolve the issue.

clearcache

Check browser extensions

If you have extensions installed on your browser, one or more of them may be causing the issue. Disable all of your extensions and then try to access the page again. If the error goes away after that, it’s most likely a plugin or extension that’s causing the problem. To locate the offender, enable your plugins one by one after that.

Restart the Devices

If you’ve used the site checker and determined that the site is down only for you, and you’ve tried a different browser with the same result, you know the issue isn’t with the server or the browser. It is probably an issue with your device.

Likely, your computer or networking gear (Wi-Fi, router, and so on) are experiencing some odd and temporary issues. This problem can be solved by restarting your computer and networking equipment.

Change DNS Servers

DNS issues can occasionally result in 502 errors. Changing DNS servers isn’t a good idea, but it’s one way of checking for errors. Your ISP will most likely set up your DNS servers unless you modify them yourself. You can change them to third-party DNS servers like Open DNS or Google DNS, which may resolve the issue. There are also other benefits of switching to DNS servers, such as improved speed and dependability.

If you are Sysadmin or Website owner, try these:

Is the backend server functional?

  • Check if backend server (ex – PHP, NodeJS, Tomcat, etc) running? If not, start it.
  • If the backend server is running, maybe it is hung? Or, not in a state to serve any request?
  • Can webserver talk to backend server? Maybe a firewall issue?

You see, there could be numerous reasons and the best way to debug is, check the web server and backend server logs to see why it can’t serve the request. Once you know what is causing the issue, you can fix that.

Temporary disable CDN or firewall.

Content delivery networks (CDN) are the Internet’s transparent backbone for content distribution. The 502 bad Gateway error could be caused by a CDN. You’re using a CDN from a third-party service.

If altering the Firewall and CD configurations does not help, consider temporarily turning them off and restarting the website. This procedure isn’t 100 percent effective, but it’s worth a shot to see what the issue is.

Wrapping Up 👨‍💻

In this article, we’ve looked at what the 502 Bad Gateway problem means, the most common causes, and how to resolve it.

502 is an error that occurs when the servers can’t communicate. By applying the above techniques, you should better understand the problem and how to fix it.