What Is 502 bad gateway Error and How to Fix It?

The 502 Bad Gateway error indicates that the server received an improper response from an incoming server. Read further to understand the causes of this error and find quick solutions for its resolution. Also, ensure a safe and secure online experience with a VPN.

What is the 502 Bad Gateway Error?

When you input a URL in your browser, a request is sent to the site’s server, which processes and displays the content. If issues arise, an HTTP status code appears. While a 404 denotes a missing page, a 502 Bad Gateway occurs when communication breaks between servers. 

The initial server relays the message but receives an invalid response from the upstream server. Essentially, the gateway server gets an invalid response, unable to fulfill the request. 

The error may manifest differently depending on your browser. Beyond proxy or server overload, let’s delve into common causes of the HTTP 502 error.

The 502 Bad Gateway Error- Causes

The 502 Bad Gateway error can happen for a few reasons:

• Domain Name Connectivity Issues: If a website recently moved to a new hosting provider, there might be connectivity issues between the domain name and your IP address.
• Overly Strict Firewall Settings: Some firewalls, like WordPress sites, can be too strict, blocking certain Internet providers or IP addresses incorrectly.
• Server Overload: A sudden surge in traffic can crash the server, especially on shared hosting plans.

It’s important to note that the 502 error isn’t only about server problems. Outdated browsers or corrupted files in the browser cache can also cause this issue on your end.

How to Fix the 502 Bad Gateway Error?

While the 502 Bad Gateway error is often linked to server issues, it can also result from client-side misconfigurations or temporary problems. Therefore, we will outline common troubleshooting steps considering both server and client aspects. While certain solutions are tailored for WordPress, most are applicable to any website.

1. Reload the Page

The initial solution is straightforward—give it a minute or two, then refresh the web page. Often, the error results from a sudden increase in traffic. A simple page refresh usually resolves it. Windows users can press F5 or CTRL + F5, and Mac users can press CMD + R. Additionally, you can use online tools like Website Planet or Host Tracker to check if the website is offline, pinpointing whether the error stems from server or client-side issues.

2. Clear Browser Cache

If the problem continues, it’s possible that your browser cache contains outdated and corrupted files. Clearing the cache can often resolve an HTTP 502 Bad Gateway error. Be cautious, as clearing cached files may result in the loss of important browser data like bookmarks and settings. To avoid this, export your data from the browser before clearing the cache, and then import it back afterward.

3. Flush DNS Servers

The error may result from DNS issues like incorrect IP addresses or unresponsive DNS servers. In such cases, resolving the problem can involve flushing your DNS cache, akin to clearing your browser’s cache, to eliminate faulty files from the DNS server. Another option is temporarily changing your DNS servers. While your ISP typically assigns them by default, you can opt for a third-party server like Google Public DNS.

4. Use Incognito Mode

Using Incognito mode can help identify if the HTTP Error 502 message is related to a browser issue. To open an Incognito window, click the three-dots button and choose New Incognito Window.

If the error doesn’t appear in Incognito mode, a browser extension may be the culprit. Gradually disable add-ons. Once you pinpoint the problematic one, you should regain access.

If disabling extensions doesn’t work, try a different browser. If the new browser loads the page correctly, your initial browser might be the issue. Consider uninstalling and reinstalling it to resolve the problem.

5. Check Error Log

If you encounter an error following a specific change or update, the problem may reside within your server. To address this, check your website error log. Hosting services typically provide access to enable the error log through an admin dashboard. For WordPress, you can activate error logging in wp-config.php by adding the following lines:

• define(‘WP_DEBUG’, true);
• define(‘WP_DEBUG_LOG’, true);
• define(‘WP_DEBUG_DISPLAY’, false);

The generated errors will be recorded in the wp-contents/debug.log file, helping you identify which ones are triggering the 502 Bad Gateway error.

6. Try a Different Device

If the previously mentioned solutions don’t resolve the HTTP error 502, assess the connection on an alternate computer or mobile device, preferably on a different network. Additionally, try restarting your PC and networking equipment. Turn off your computer and unplug the wireless router, then wait briefly before plugging them back in. This step assists in determining if the error is associated with your networking equipment or if the issue extends beyond.

7. Verify CDNs

Another potential cause of 502 Bad Gateway errors could be issues with your Content Delivery Network (CDN) or DDoS mitigation services.

A CDN acts as an intermediary layer between your server and the browser, enhancing the efficient delivery of web content. However, this layer might encounter problems when connecting with your origin server, leading to 502 Errors.

For instance, in the case of Cloudflare, the 502 Bad Gateway error can manifest in two variations depending on the nature of the issue.

If you encounter the Cloudflare 502 error, it indicates a problem on Cloudflare’s side. To resolve it, contact their customer support team, and be sure to check the Cloudflare System Status page before doing so.

On the other hand, if you see the Cloudflare error mentioned above, it signifies an issue with your current hosting provider. In this scenario, reach out to your web host’s support team for assistance. Keep in mind that disabling Cloudflare is an option, but note that DNS propagation may take a few hours.

8. Check the Status of the Site

If you continue to encounter the 502 Error code despite attempting various methods, there’s a possibility that the origin server is currently undergoing downtime. Fortunately, numerous online tools, such as Down for Everyone or Just Me and IsItDown, can help you assess if a site is down. Enter your URL into these tools to check the status of your website.

9. Contact Hosting Provider

If you’ve followed the earlier steps without success, it’s advisable to reach out to your hosting provider. There could be a server-related problem impacting your site. If this is the case, your best course of action is to wait for them to address and resolve the issue.

Moreover, your hosting provider might be able to pinpoint the origin of the 502 Bad Gateway error and guide you through a solution. Many hosts provide 24/7 support through chat, ensuring a swift resolution to the issue.

10. Reboot PHP and Raise PHP Limits

The 502 Gateway Error might stem from a PHP timeout issue, occurring when the PHP process exceeds the maximum load time, leading to a timed-out request.

Restarting PHP could potentially resolve connectivity problems. Most hosting providers offer an option to restart services through your control panel. If not visible, you can inquire with them to perform the restart.

In some cases, adjusting your server’s max_execution_time or max_input_time values may be necessary. While WordPress defaults to 300 seconds for these values, you can extend PHP execution time either through your host’s control panel or by seeking assistance from their technical support.

Different Forms of 502 Bad Gateway Errors

This error can manifest across various browsers, operating systems, and services, but its appearance varies. Here are different forms you might encounter:

• 502 Error
• 502 Bad Gateway Nginx
• HTTP Error 502 Bad Gateway
• 502 Proxy Error
• 502 Service Temporarily Overloaded
• 502 Server Error: The server encountered a temporary error and could not complete your request
• 502 – Web server received an invalid response while acting as a gateway or proxy server
• Bad 502 Gateway
• 502 Error
• HTTP 502
• Temporary Error (502)
• Error 502
• A blank white screen

Note that certain websites or services may have custom 502 Error pages, presenting a different appearance.

Error Status Codes Resembling 502 Bad Gateway

Comprehending error codes is crucial for website owners and developers to promptly identify and resolve issues. Besides HTTP 502 Errors, your website may encounter various status error codes. Some common ones include:

• 501 Not Implemented: Signals that the server lacks the functionality to fulfill a particular request.
• 403 Forbidden Error: Arises when the web server restricts visitors from accessing specific content.
• 503 Service Unavailable: This indicates the server is currently down for maintenance and cannot process the request.
• 504 Gateway Timeout: Occurs as a result of a proxy error when waiting too long for a response from the upstream server.
• 404 Page Not Found: Indicates a response sent when the requested web page is unavailable.

Conclusion

A 502 Bad Gateway error occurs when a gateway server gets a wrong response from the main server. Ignoring this error can hurt your conversion rate, user experience, and page rankings.

This issue is mainly on the server side, not your website, internet, or computer. Check for broken plugins or themes too. Follow these steps to fix errors and get your site back on track.