What Is a 500 Internal Server Error (and How to Fix It)

The 500 Internal Server Error is one of the most frustrating errors because it's so vague. It means something has gone wrong on the website's server, but the server can't be more specific about what the exact problem is. Our tool can confirm the site is down, but this guide will help you (or your developer) figure out why.

What Is a 500 Internal Server Error?

A 500 Internal Server Error is a general-purpose HTTP status code. It means that the server encountered an unexpected condition that prevented it from fulfilling the request. It's a "catch-all" error that the server gives when no other, more specific 5xx error code applies.

Unlike a 404 error (which means the *page* is missing), a 500 error means the *server itself* has a problem.

Common Causes of 500 Errors

This error is almost always a server-side issue. As a visitor, there's nothing you can do to fix it. As a site owner, here’s where to start looking:

1. Corrupted .htaccess File

The .htaccess file is a powerful configuration file used by Apache servers. A single syntax error, like a typo or an incorrect rule, can bring the entire site down with a 500 error.

  • How to check: Connect to your server via FTP or your host's File Manager.
  • How to fix: Rename your .htaccess file to something like .htaccess_old and try reloading your site. If the site loads, this was the problem. You can then generate a new, default .htaccess file (in WordPress, you can do this by just visiting Settings > Permalinks and clicking "Save").

2. Issues with Plugins or Themes

This is the most common cause for content management systems (CMS) like WordPress. A newly installed, recently updated, or poorly coded plugin or theme can conflict with the server or other plugins.

  • How to check: If you can access your admin dashboard, deactivate all plugins. If the error goes away, reactivate them one by one until the error returns. The last plugin you activated is the culprit.
  • If you can't access your admin: Use FTP to navigate to your /wp-content/ folder and rename the plugins folder to plugins_disable. This will deactivate all plugins. If the site comes back, rename the folder back to plugins and then deactivate them one-by-one from within the dashboard.

3. Exceeded PHP Memory Limit

Your server allocates a specific amount of memory to run scripts (like WordPress and its plugins). If a process requires more memory than is available, it can trigger a 500 error.

  • How to fix: You can increase the memory limit by editing your wp-config.php file or php.ini file. Add this line to wp-config.php: define('WP_MEMORY_LIMIT', '256M');. If this doesn't work, contact your hosting provider and ask them to increase the PHP memory limit for your account.

4. Corrupted Core Files

Sometimes, the core files of your CMS (like WordPress itself) can become corrupted, often during a failed update.

  • How to fix: Download a fresh copy of WordPress from WordPress.org. Unzip it, and then upload and overwrite the existing /wp-admin/ and /wp-includes/ folders on your server via FTP. This re-installs the core files without touching your content.

5. Check Server Error Logs

This is the most direct way to find the problem. Your server keeps a log of all errors. Log in to your hosting control panel (like cPanel) and look for an "Error Log" icon. Open it and look at the most recent entries. The log will often state the exact file and line of code that is causing the fatal error, pointing you directly to the problem.