500 Error: Causes, Impacts and Solutions to Fix “Internal Server Error”

The 500 error, also known as the “Internal Server Error”, is one of the most frustrating errors you can run into as a site owner or user. Unlike a 404 error, which indicates that a page can’t be found, a 500 error means that something is wrong on the server side, without specifying exactly what.

In this article, we’ll explore:

• The impact of this error on SEO and user experience.
• What a 500 error is.
• The main causes of this error.
• Practical solutions to fix the 500 error.

Need help with other errors? Check out our complete guides on HTTP errors 404, 403, 502, 504, 429, 401, 400 and 410 to understand their causes, impacts and solutions.

What is a 500 error?

A 500 error indicates a server-side problem that prevents a web page from displaying correctly. It means the server encountered an unexpected condition that prevents it from processing the request.

How does the 500 error appear?

It can appear in different forms, depending on the server or browser being used:

It can appear in different forms, depending on the server or browser being used:

• “500 Internal Server Error”.
• “HTTP Error 500”.
• “Internal Server Error”.
• “Internal Server Error”.

Why is it important to fix the 500 error?

Impact on user experience:

• A 500 error makes a site inaccessible, which can frustrate users.
• Visitors quickly leave the site, thereby increasing the bounce rate.

Impact on SEO:

• If Googlebot encounters repeated 500 errors, it can harm your site’s indexing.
• An inaccessible page sends a negative signal to Google, which can affect your ranking in search results.

To learn more about the impact of server errors on SEO, see our guide on 404 HTTP errors and how to fix them.

The main causes of a 500 error

Issues related to the .htaccess file:

• A misconfiguration of the .htaccess file can cause a 500 error.

File permission issues:

• Incorrect permissions on files or folders (example: 777 permissions) can cause errors.

Memory or execution time limits exceeded:

• If a script exceeds the limits allocated by the server, a 500 error can occur.

Issues in PHP scripts:

• An error in the PHP code, such as incorrect syntax or a conflict between plugins, can trigger an internal error.

Issues related to the web server:

• The server may be overloaded or misconfigured.

Misconfigured databases:

• An incorrect database connection or a corrupted database can also be the cause.

For more information on managing server files, see Apache’s official guide: Apache HTTP Server Logs.

How to diagnose a 500 HTTP error?

Check the server logs:

• Server logs contain detailed information about errors.
• Log location:
  • Apache: /var/log/apache2/error.log.
  • Nginx: /var/log/nginx/error.log.

Enable debug mode:

• In PHP, add this code to display errors:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

Check the .htaccess file:

• Temporarily rename the .htaccess file to .htaccess_old to see whether the error disappears.

Test your plugins or extensions:

• Temporarily disable plugins or extensions to identify a possible conflict.

Check file permissions:

• Make sure file permissions are correct (644 for files and 755 for folders).

Solutions to fix a 500 HTTP error

Fix errors in the .htaccess file:

• If the problem comes from the .htaccess file, generate a new one by resetting the permalinks in WordPress or by creating a file with the basic configurations.

Increase memory limits in PHP:

• If the error is due to a lack of memory, add or modify this line in the php.ini file:

memory_limit = 256M

Fix errors in PHP scripts:

• Examine your PHP files to detect syntax errors or deprecated function calls.

Temporarily disable plugins or themes:

• If you’re using WordPress, rename the wp-content/plugins or wp-content/themes folder to temporarily disable extensions and themes.

Restart the server:

• Sometimes, a simple server restart can solve the problem.

Check the database configuration:

• Make sure the credentials and permissions are correct in the configuration file (for example, wp-config.php in WordPress).

To optimize your WordPress site, see our article on best practices for WordPress maintenance.

Best practices to avoid 500 HTTP errors

Make regular backups:

• Back up your files and databases before any change.

Monitor server performance:

• Use tools like New Relic or Pingdom to detect overloads or server problems.

Update your site regularly:

• Keep your CMS, plugins and extensions up to date to avoid incompatibilities.

Optimize your scripts:

• Remove unused scripts and optimize those that consume a lot of resources.

Conclusion

The 500 HTTP error may seem complex to fix, but with a structured approach, it’s possible to identify and resolve the underlying cause. By taking preventive measures such as regular backups, monitoring server performance and updating your scripts, you can prevent this problem from happening again.

For problems that persist, it’s recommended to consult an expert in development or server administration. By fixing 500 errors quickly, you improve not only the user experience, but also your site’s organic search ranking.

To prevent this error from happening again, follow the best practices mentioned and regularly monitor errors via Google Search Console. If you want to learn more about other HTTP errors, explore my articles on errors 404, 403, 502, 503, 504, 429, 401, 400 and 410 for detailed solutions!