July 28, 2023Read More
A guide to HTTP 500 server error codes and their meanings
Posted by Scott Harrington, May 26, 2023
If you have spent any amount of time on the internet, you have probably encountered a few HTTP (Hypertext Transfer Protocol) status codes. There are a wide range of these three-digit codes, all with different meanings.
- 1xx codes: HTTP status codes in the 100s are informational codes indicating that the request has been received and the server is processing it.
- 2xx success codes: 200 OK, 201 Created, and 204 No Content codes all indicate that the request has been successfully received and understood by the server.
- 3xx redirection codes: status codes in the 300s indicate that the requested resource has been moved permanently or temporarily to a new location and that the client needs to take additional steps to complete the request.
- 4xx client error codes: These error codes indicate that there has been an error on the client's side, such as that the requested resource could not be found or that the syntax is invalid.
And, finally, there are the 5xx errors, including the common HTTP 500 Internal Server Error. This indicates a problem on the server's side, and while reloading the page and clearing your browser history and cookies can sometimes help you get past a 500 error on someone else's website, troubleshooting a 500 internal server error on your own website can be a little trickier.
Today, we'll take a closer look at the error code HTTP 500, explaining how to diagnose the causes of this status code and what to do to resolve the issue on your website.
HTTP 500 internal server errors explained
An HTTP 500 internal server error means that the server has not been able to fulfil the request because of an unexpected problem. This is the most generic 5xx status code and does not give a specific cause for the problem, so it's up to you to figure out what the issue is. In contrast, the other 5xx error codes indicate the cause of the problem:
502 Bad Gateway: The server acting as a proxy or gateway receives an invalid response from the upstream server, often because the upstream server is temporarily unavailable.
503 Service Unavailable: The server cannot currently handle the request due to high load or maintenance.
504 Gateway Timeout: The upstream doesn't give a timely response, for example if it has network connectivity issues or is overloaded.
More than just being irritating for website users, 500 internal server errors can have a detrimental impact on your SEO if they persist over time. This is because sites that regularly return 500 Internal Server Errors will be crawled less often and may even be dropped from Google's index. For this reason, it's important that you troubleshoot and resolve 500 Internal Server Errors quickly and effectively.
What causes HTTP 500 Internal Server Errors, and how do I troubleshoot them?
Because HTTP error 500 is a generic error code that doesn't indicate the cause of the problem, it's down to you to identify and troubleshoot the issue.
The first step is to make sure that the problem is not on your end - sometimes 500 Internal Server Errors are a result of cache and cookie problems in your browser. To check, clear your cookies and internet history before reloading the page to see if the problem persists.
Your next step is usually to look at the server logs which can provide more information about the error. If there are specific error messages these can allow you to pinpoint the source of the problem. For example, you may find that a particular module or file is the source of the issue. You may need to ask your service provider to access the error logs.
Here are some of the causes of HTTP 500 Internal Server Errors and how to check for them.
Improper configuration of the server software
Misconfiguration of the web server or application server can contribute to 500 Internal Server Errors due to missing files, incompatible modules, security issues, or incorrect settings. Carefully checking the server configuration against the server software's guidelines can help you identify problems with the settings.
Issues with .htaccess
One of the common causes of this HTTP status code is a problem with .htaccess. In short, .htaccess is a text file that contains server instructions which tells the software which functions to enable or disable. For example, .htaccess defines user access permissions and protects passwords in a directory, and defines how long resources should be stored in a browser's cache. If .htaccess is broken or corrupted, this can cause HTTP status error code 500.
To check whether a problem with .htaccess is causing your error message, review the file for syntax and formatting errors which might be behind the issue. Make sure to backup the original .htaccess file and then temporarily disable it to see if the problem is resolved. If the problem is resolved, this may indicate that the server configuration and the file are in conflict, so check the internal server configuration settings. You may also choose to isolate each .htaccess directive and test the website to identify if one particular factor is causing the problem.
If your application encounters problems while interacting with a database, this can cause a HTTP 500 Internal Server Error. For example, an issue with the database connection or database server failures can lead to this error response code. Check the database logs to see if this is the source of the problem.
Insufficient server resources
Resource limitations can be another cause of HTTP 500 response codes. In these cases, the server doesn't have enough resources to handle the request because of limited CPU or disk space. Often, this happens if there is high traffic or when the server is overloaded.
You can check whether this is the cause of your 500 errors by monitoring resource usage using metrics such as CPU utilisation, memory usage, and network traffic, for example. You can also check server logs for any entries such as disk write failures or memory allocation errors which might indicate that the server resources are insufficient. Finally, testing and monitoring server response times can help you identify problems with server performance.
If the limited CPU, memory, or disk space is causing the problem, you may need to upgrade the server hardware or reallocate resources in a more optimal way to resolve the Internal Server Error.
PHP memory limit
The Internal Server Error may also be caused by the PHP memory limit. When PHP (a scripting language used to manage content, databases, session tracking, and more) exceeds the website's memory limit, you may see the HTTP 500 status code.
To understand whether the memory limit of PHP being reached is causing your error code, check the error message or log to see if phrases like "exhausted memory" or "memory allocation error" indicate a PHP issue. Enabling error display in your PHP code or configuration also lets you see errors relating to the memory limit.
Issues with plugins
Incorrect configuration or problems with plugins and themes can also result in this error message. If the plugin or theme has bugs, is experiencing connectivity issues, or is incompatible with the server environment, these factors can all contribute to 500 HTTP status codes.
To check whether plugins are the cause of your 500 error code, look for outdated plugins that are no longer compatible, or conflicts between different plugins. Try deactivating or uninstalling your plugins one at a time to figure out which one is causing this error in your web server.
Programming bugs and errors
HTTP 500 errors are sometimes triggered by problems with the application code and programming which cause unexpected conditions on the server. For example, if the code crashes or can't handle the scenario properly, you are likely to see this error. To check for this issue, review the application code and look for any programming errors.
How to resolve 500 errors
In an ideal world, you will be able to quickly identify the source of the issue and resolve it. Often, ensuring that server software, third-party plugins, and application frameworks are up to date and applying all security updates and bug fixes can quickly and simply resolve the issue. Deactivating plugins and themes and checking .htaccess also usually help solve the issue.
However, sometimes the problem is hard to isolate and fix. Here's what to do next if you';re still struggling with 500 errors.
Consult troubleshooting guides or forums
Looking at relevant troubleshooting guides and documentation or visiting online forums can help by providing insight into the causes of your 500 Internal Server Error. Guides with step-by-step troubleshooting instructions are extremely useful for solving specific problems. If these don't cover your specific issue, looking for information from people who have encountered similar problems in relevant forums can be a useful next step.
Use a staging environment
One way that developers can investigate 500 errors is by creating a staging environment for testing. This makes it easier to troubleshoot the application without impacting the live website. Within the staging environment, you can try out different code changes and configurations to identify the cause of the error and figure out how to fix it without affecting your website's live performance.
Get support from your web developers
If you can't find a solution on your own, consulting a web developer is essential. A professional web developer with expertise in your software or framework can provide guidance and enact fixes to resolve the HTTP error 500 and reduce the risk of it reoccuring. A comprehensive web maintenance and support package from your web development agency is a worthwhile investment to keep your website functioning effectively.
While HTTP 500 errors on your website may be annoying and confusing, they can usually be resolved swiftly by applying updates and bug fixes. More complex causes of these errors can be handled easily by web developers and technical experts. If you are dealing with persistent 500 errors or want additional technical support with your website, get in touch with Ryde web development agency today.