Have you ever tried to access a website, only to be met with a 502 Bad Gateway error? This HTTP status code indicates an error in communication between two servers and can be caused by a variety of factors. In this article, we will explore what the 502 Bad Gateway error is, what causes it, and how to fix it using easy troubleshooting steps.
HTTP status codes are used to indicate the response status of a server. They are grouped into five categories: informational, success, redirection, client error, and server error. The 502 Bad Gateway error falls under the server error category, indicating a communication error between two servers.
Causes of 502 Bad Gateway Error
There are several reasons why you may encounter a 502 Bad Gateway error. These include:
Unresolved Domain Name
One of the most common causes of the 502 Bad Gateway error is an unresolved domain name. This can happen if the domain name system (DNS) is not configured correctly, or if the DNS server is down or unresponsive.
Origin Server Overload
If the origin server is overloaded, it may struggle to handle requests and return a 502 Bad Gateway error. Some common reasons for server overload include sudden spikes of traffic, low memory, and software timeouts.
Browser errors such as faulty browser extensions like ad-blockers, outdated browser versions, or corrupted files in your browser cache can cause browser errors. These errors can lead to a 502 Bad Gateway error when trying to access a website.
Home-Network Equipment Issues
Issues with home-network equipment can also cause a 502 Bad Gateway error. For example, if there is an issue with your router or modem, it may struggle to communicate with the server and return a 502 Bad Gateway error.
Firewall blocks can prevent access to certain websites, resulting in a 502 Bad Gateway error. These blocks can be caused by software or hardware firewalls that are configured to block specific websites or IP addresses.
How to Fix 502 Bad Gateway Error
If you encounter a 502 Bad Gateway error, there are several easy ways to fix it. Here are some troubleshooting steps you can take:
Refresh the Page
Sometimes, refreshing the page can fix a 502 Bad Gateway error. This is because the error may be temporary and a refresh can help re-establish the connection.
Clear Browser Cache
Clearing your browser cache can help fix browser errors that may be causing the 502 Bad Gateway error. This is because the cache may contain corrupted or outdated files that are causing the error.
Try in Incognito Mode
Trying to access the website in incognito mode can help isolate the issue. If the website loads in incognito mode, it may indicate that faulty browser extensions are causing the 502 Bad Gateway error.
Flush DNS Servers
Flushing your DNS cache can help fix DNS problems such as incorrect IP addresses and unresponsive DNS servers. This is because flushing the cache forces your computer to retrieve the latest DNS information.
Test on Another Device
Testing the website on another device can help determine if the issue is with your device or the website itself. If the website loads on another device, it may indicate that the issue is with your device.
6. Check Error Log
An error log is an essential tool for troubleshooting your website when it experiences an error. It can provide you with valuable information that can help you identify the root cause of the 502 Bad Gateway Error. To check your website error log, follow these steps:
- Check your hosting service to enable a website error log through an admin dashboard.
- Enable error logging on your WordPress site by adding the following lines in wp-config.php:
define( 'WP_DEBUG', true ); define( 'WP_DEBUG_LOG', true ); define( 'WP_DEBUG_DISPLAY', false );
- All of the generated errors will appear in the wp-contents/debug.log file, allowing you to detect which ones are causing a 502 Bad Gateway error.
7. Check Plugins and Themes
One of the reasons for the 502 Bad Gateway Error could be faulty plugins or themes. Poorly coded plugins and themes can conflict with each other, leading to the server stopping every script and query on your website, making it inaccessible. Here are some ways to fix this:
- Disable your plugins and re-activate them one by one. Go to Plugins and click Deactivate from the Bulk Actions menu. Activate each plugin while refreshing your WordPress site after each one. Once the 502 Error pops up again, you have found the problem plugin.
- If you can’t access your WordPress dashboard, try disabling plugins from your hosting panel or FTP program. Navigate to the wp-content directory and rename the plugins directory, for example, plugins-disable.
- If the website still doesn’t work, follow the same steps with your WordPress themes.
8. Check CDNs
A content delivery network (CDN) adds an extra layer between your server and browser to efficiently deliver web content. However, this layer can run into an issue when connecting with your origin server, resulting in 502 Errors. To fix this:
- Check the CDN service status page to ensure that it’s not down.
- Disable your CDN, though keep in mind that your DNS propagation may take a couple of hours.
9. Check the Site Status
If the 502 Error code is still showing up despite trying most of the methods so far, it is possible the origin server might be currently experiencing downtime. You can check if a site is down by using tools such as Down for Everyone or Just Me and IsItDown. Simply input your URL and check the status of your website.
10. PHP max_execution_time and max_input_time
A PHP timeout happens whenever a PHP process loads for more than the specified max_execution_time or max_input_time. These are the values set in your PHP configurations on your web server. Usually, the values are set to 300 seconds by default. To fix this issue:
- Talk to your web host to check what your values are set at and if you can increase them.
Contact Customer Support
If none of the above solutions works, it is best to contact the customer support team. They can help identify the root cause of the error and provide a solution to fix it.
How 502 Bad Gateway Error Affects SEO
502 Bad Gateway errors can have a significant impact on SEO. This is because they can cause website downtime, which can lead to a drop in search engine rankings. Additionally, if users encounter frequent 502 Bad Gateway errors, they may lose trust in the website, which can result in a lower click-through rate and a decrease in traffic.
Error Status Codes Similar to 502 Bad Gateway
There are several other HTTP status codes that are similar to the 502 Bad Gateway error. These include:
- 500 Internal Server Error
- 501 Not Implemented
- 503 Service Unavailable
- 504 Gateway Timeout
502 Bad Gateway FAQ
What is a 502 Bad Gateway error?
A 502 Bad Gateway error is an HTTP status code that indicates an error in communication between two servers.
What causes a 502 Bad Gateway error?
The causes of a 502 Bad Gateway error can be numerous, from minor browser-related issues to problems with CDNs.
How can I fix a 502 Bad Gateway error?
Some easy ways to fix the 502 Bad Gateway error include refreshing the page, clearing the browser cache, trying in incognito mode, testing on another device, checking the error log, checking plugins and themes, checking CDNs, checking the site status, and increasing PHP max_execution_time and max_input_time values.
In summary, the 502 Bad Gateway error can be caused by various factors, including unresolved domain names, origin server overload, browser errors, home-network equipment issues, and firewall blocks. Troubleshooting steps such as refreshing the page, clearing the browser cache, and checking plugins and themes can help fix the error.
Remember, if none of these solutions works, it is best to contact customer support. By addressing the 502 Bad Gateway error, you can improve website performance and user experience, ultimately contributing to a better SEO ranking.