What does the 502 status code mean?
There is nothing worse than trying to access a web page only to be faced with a haunting 502 Bad Gateway Error message. This error is an HTTP response status code signaling that one server on the internet received an invalid response from another server. This server-side error mainly pops up due to a couple of reasons – an issue between the communicating online servers or DNS issues such as incorrectly cached IP addresses. Sometimes there is no issue at all, but your server might perceive one due to an underlying problem with your browser or home networking equipment. Most error messages in the 5xx category are server-side errors, meaning the issue is on the web server hosting the web page and not on your side.
In the next section, let us peek into the various types of 502 errors and the ways they can be phrased by different web servers.
The different types of 502 status code errors
A 502-error message can be presented in vast variations. Even though all 502 status code errors are Bad Gateway errors, web servers can sometimes customize and present them differently. Here are some common phrases that you might stumble across when viewing a 502-error message:
- 502 Bad Gateway;
- 502 Service Temporarily Overloaded;
- Error 502;
- Temporary Error (502);
- 502 Proxy Error;
- 502 Server Error: The server encountered a temporary error and could not complete your request
- HTTP 502;
- 502. That’s an error;
- Bad Gateway: The proxy server received an invalid response from an upstream server;
- HTTP Error 502 – Bad Gateway.
Interesting fact: Twitter’s famous “fail whale” image that declares that Twitter is over capacity is in fact a 502 Bad Gateway error.
Now that we understand the gist of this error message, let us deep-dive into the underlying causes of this message.
Common causes behind the 502 errors
As discussed earlier, this error message is generated when the server you tried to reach was not able to resolve the request. However, several other reasons can also cause this error to appear. Here are a few key reasons behind this error message.
1. The source or origin server is out of order
This simply means the origin server is not accessible or working properly. Connectivity issues with the server, a spike in the traffic pattern on the server, or the fact that the server is powered down could all be the potential culprits.
2. DNS Issues
DNS issues are another common source for the 502 error messages. Sometimes the domain name does not resolve to the right IP address due to incorrect DNS records that are set at the hosting level. It is important to keep in mind that any DNS change takes time to propagate to the DNS records due to the TTL or time to live threshold. Therefore, this delay can also sometimes generate the 502 Bad Gateway error message.
3. Firewall blocks
If you are behind a firewall, it could very well be the reason for the 502 error. An active firewall can block transmission between servers. In some instances, the WordPress security plugins might block the communication or even put a block on your local IP. To resolve this, you should try to access the blocked site from a different internet connection or explicitly allow the site in your firewall settings. It is important to note here that many DDOS protection systems are over-protective and most inbound requests are automatically blocked.
4. Server Failure
If a server completely fails, then a 502 error will be generated. A server failure could be due to a system crash or a server being simply taken down due to maintenance reasons. In some rare cases, the content hosted on the server might be in direct violation of the server provider’s terms and conditions.
5. Browser Errors
Certain browser extensions can lead to erroneous errors while rendering a website and could cause a 502-error message, particularly in the case of AdBlock extensions. Outdated browser versions could also generate this error message in some instances.
Now let us shed some light on the different ways of fixing this error message in the next section.
How to fix the 502 status code error messages
As a site owner, you want to ensure that your website is always up and running. Whether it is a WordPress or a Wix based website, here are few ways that you can implement to ensure a seamless web experience free of any 502 error messages:
1. Reload the website
Sometimes, due to network congestion, the server might take longer to respond than usual. The simple solution is to just wait and reload your website and, in most cases, this should fix the nasty 502 error for good.
2. Clear the browser cache
Caching is a helpful mechanism for speeding up web browsing but it can sometimes cause the 502-error message if the browser is loading the website from the cache. The easy fix is to clear out your browser’s cache and then give it a try again.
3. Disable the firewall
A firewall is an additional layer of security between your browser and the hosting server, but it can sometimes block traffic unnecessarily. If you are behind a CDN Service or a Firewall, try disabling it first to make sure the issue is actually with the firewall. If after disabling the firewall, the 502 error disappears, then you are good to go!
4. Update the themes and plugins
At times, various plugins can cause issues and generate the 502 error. To rectify this, simply disable all the plugins and see if this resolves the issue. If it does, then one of the plugins was the culprit and then you can go and activate each plugin one by one until you get to the one that caused the block. If the plugin methodology fails, then the issue could be with one of your website themes. In this case, it would be best to try updating the theme to a new one and then re-checking to see if the 502-error message has disappeared or not.
5. Check the hosting server
If all else fails, then the issue could very well be with your hosting server. In this case, try contacting their support team and describe all the triaging you have conducted up till now. If the issue is indeed caused by a hosting server, then they should be able to rectify it.
Check the website for 502 status code
Audit your website to detect whether the site has pages with 502 HTTP status code