How to Fix the 500 Internal Server Error in WordPress (In-Depth Guide)

Few things are as frustrating as seeing the ominous "500 Internal Server Error" message pop up when trying to access your WordPress website. This common HTTP status code indicates that something has gone wrong with the server, but it doesn‘t specify exactly what the problem is.

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Don‘t panic, though – in most cases, the 500 internal server error can be resolved relatively quickly by following some basic troubleshooting steps. As a WordPress consultant and web developer, I‘ve helped many clients get their sites back up and running after encountering this error.

In this comprehensive guide, I‘ll walk you through the most effective solutions for fixing the 500 internal server error in WordPress. But first, let‘s take a closer look at what this error means and some of its potential causes.

Understanding the 500 Internal Server Error

The 500 internal server error is a generic HTTP status code that means something has gone wrong on the web server, but the server can‘t specify what the exact problem is. When you visit a website, your browser sends a request to the site‘s server, and the server responds with a three-digit HTTP status code like 200 (OK) or 404 (Not Found).

A 500 status code indicates a server-side error, meaning the problem is not with your internet connection or browser. This makes troubleshooting trickier since the error could stem from a variety of issues, such as:

  • Corrupted .htaccess file
  • Exhausted PHP memory limit
  • Plugin compatibility issues
  • Theme functions errors
  • Incorrect file permissions
  • Corrupted WordPress core files
  • Problems with the web server itself

With that background in mind, let‘s dive into how to go about fixing the dreaded 500 error on your WordPress site.

Steps to Fix the WordPress 500 Internal Server Error

Follow these troubleshooting steps in order until you resolve the issue. Be sure to test your site after each step to see if the error is fixed.

Step 1: Enable Debugging Mode

Before attempting any fixes, it‘s wise to enable WordPress debugging mode to gather more details about the error. Debugging mode will display specific error messages on your site‘s front-end to indicate the cause.

To turn on debugging mode, open up the wp-config.php file in your WordPress site‘s root directory. Add this line of code:

define(‘WP_DEBUG‘, true);

You can find out how to access this file and edit it via FTP from your web host‘s documentation. Be sure to disable debugging mode once you‘re done troubleshooting by setting this value back to "false". You don‘t want to leave it enabled long-term as it can expose sensitive data.

Additionally, check your server logs if your host provides access to them via cPanel or another control panel. The server logs may contain clues pointing to what‘s causing the error.

If the error messages provide insight into a specific plugin, theme, or script that may be malfunctioning, that gives you a solid lead for what to investigate further in the following steps.

Step 2: Regenerate the .htaccess File

The .htaccess configuration file in your site‘s root directory (at the same level as the wp-content and wp-includes folders) controls several key settings for your WordPress installation. If this file has become corrupted, it can trigger 500 errors.

The fastest way to rule this out is to temporarily delete your .htaccess file. Don‘t worry, WordPress will generate a new default one.

Connect to your site via FTP or use the file manager in your host‘s control panel. Rename the .htaccess file to ".htaccess_old" or something similar. Now try loading your site. If it works, you know the previous .htaccess file was the culprit.

While you could just stick with the new .htaccess file WordPress creates, it‘s better to restore your previous settings if you customized the file previously (such as adding rewrite rules). Go to Settings > Permalinks in your WordPress dashboard and re-save your permalink structure to regenerate a fresh .htaccess file containing the standard WordPress rewrite rules.

If deleting .htaccess doesn‘t resolve the error, continue to the next step. And if you can‘t find this file at all, your server may be running Nginx instead of Apache, in which case you can skip this solution.

Step 3: Increase the PHP Memory Limit

By default, WordPress allocates 32MB of memory for PHP to execute scripts. However, memory-hungry plugins and themes may exceed this limit, inducing 500 errors.

To increase your site‘s PHP memory limit, edit the wp-config.php file and insert this one line:

define(‘WP_MEMORY_LIMIT‘, ‘256M‘);

This bumps the memory allocation up to 256MB. You can specify a different value, but avoid going over 512MB – else, you may hit your server‘s physical memory limits.

If you can‘t access wp-config.php directly, look for an option in your hosting control panel, such as MultiPHP INI Editor in cPanel, to change the PHP memory limit. Boost it to 128MB or 256MB there. Alternatively, create a blank php.ini file, add this line, and upload it to your site‘s root directory:

memory_limit = 256M

Once you‘ve upped the memory limit, refresh your site to see if the error goes away. If not, try the next step.

Step 4: Deactivate All Plugins and Themes

One of the most common causes of the 500 internal server error is compatibility issues with plugins or themes. The fastest way to identify if a plugin or theme is the root of the problem is to disable them all at once. Then you can reactivate them one by one to pinpoint the culprit.

If you can still access the WordPress dashboard, head to the Plugins screen. Select all plugins, choose "Deactivate" from the bulk actions dropdown menu, and click "Apply". Next, navigate to the Themes screen and activate a default theme like Twenty Twenty-One.

Check your site again. If it loads without the 500 error, you know one of the plugins or your theme was at fault. Switch the theme back and reactivate the plugins one at a time, testing your site after each activation, until you find the precise extension that‘s generating the error.

If you can‘t get into your WordPress dashboard, you can disable plugins and themes via FTP:

  1. Access your site‘s files via FTP and navigate to the /wp-content directory.
  2. Rename the "plugins" folder to something like "plugins-deactivated". This disables all plugins.
  3. Now rename your current theme‘s folder within /wp-content/themes. This will force WordPress to revert to a default theme.
  4. Refresh your site. If the error disappears, rename the "plugins-deactivated" folder back to "plugins". Then rename each plugin folder inside it one by one, retesting your site after each change, to root out which plugin is acting up. If the error persists, repeat the process for renaming your theme‘s folder.

After identifying the faulty extension, you can either remove it entirely, contact the developer for support, or post in the WordPress.org support forums for that plugin/theme to troubleshoot.

Step 5: Repair File and Directory Permissions

Incorrect file permissions in the WordPress root directory and its subdirectories can mess with how WordPress functions, triggering 500 errors. Permissions dictate which users can read, write to, and execute files. If the permissions are too restrictive, the web server won‘t be able to execute functions in PHP files, for example.

To resolve permission issues, connect to your site via FTP and locate the file permissions settings. Usually, clicking a file or folder will reveal a "File Permissions" area where you can edit the numeric permission value.

The recommended permissions values are:

  • 755 or 750 for directories
  • 644 or 640 for files
  • 440 or 400 for wp-config.php specifically

Select all the directories in your WordPress installation, click on "File Permissions", and make sure the numeric value is set to 755 or 750 (they‘re equivalent for these purposes). Do the same for all files, but set them to 644 or 640 instead. Finally, change wp-config.php to 440 or 400.

Reload your site after correcting the permissions. If it doesn‘t resolve the error, you may need to use the harsher 777 permissions for directories and 666 permissions for files temporarily as you continue troubleshooting. But be sure to revert these changes immediately once you‘ve fixed the error as 777 and 666 leave your site vulnerable to hacks and file corruption.

Step 6: Re-upload Core WordPress Files

Occasionally, 500 errors happen because WordPress‘s core files have become corrupted. Re-uploading the /wp-admin and /wp-includes directories can resolve this.

Download a fresh copy of WordPress from WordPress.org and unzip it on your local computer. Delete the /wp-content folder and wp-config-sample.php file from the downloaded files (you don‘t want to overwrite your site‘s content, plugins, themes, and configurations). Now use FTP to upload the remaining files to your site‘s root directory. This will overwrite your existing wp-admin and wp-includes folders as well as all files in the root directory.

Before re-uploading, you may need to delete the existing wp-admin and wp-includes folders on your server and set the temporary 777/666 permissions described earlier to permit overwriting core files. Reset the recommended permissions immediately after uploading. Then test your site again.

Step 7: Consult Your Web Host

If none of the above steps cleared the 500 internal server error, your last resort is contacting your web hosting provider. There could be an actual problem with the web server itself that‘s out of your control. A quality managed WordPress host will be happy to help you track down what‘s causing the error and resolve it for you.

Even if you do fix the error yourself, it‘s smart to touch base with your host to let them know what happened in case it suggests a broader issue with their servers or your account.

How to Prevent 500 Internal Server Errors on WordPress

While the 500 internal server error is sometimes unavoidable, there are some best practices you can follow to minimize the chances of it popping up on your WordPress site:

  • Carefully vet plugins and themes before installing them on your site. Make sure they‘re compatible with your version of WordPress and well-maintained by the developer.
  • Keep your WordPress version, plugins, and themes updated to ensure you have the latest bug fixes and security patches. Consider setting up automatic updates in WordPress.
  • Regularly back up your WordPress database and files so that you can quickly restore your site if anything goes wrong. Many hosts offer daily automated backups.
  • Upgrade to a more powerful web hosting plan if you‘re constantly bumping up against memory limits and other server resources as your site grows.
  • If you‘re not comfortable troubleshooting errors yourself, consider signing up for a managed WordPress hosting package where the host handles all technical issues for you.

Useful Resources

If you need additional assistance fixing the 500 internal server error on your WordPress site, here are some resources worth checking out:

If troubleshooting becomes too overwhelming or time-consuming, consider hiring a professional WordPress developer to diagnose and fix the issue for you quickly. Look for someone with positive reviews who has dealt with 500 errors before.

The Bottom Line

I hope this in-depth troubleshooting guide gives you the knowledge and confidence to tackle the 500 internal server error on your WordPress site. With some patience and persistence, you should be able to get your site back online.

Remember, the 500 error rarely signifies a critical problem. It‘s usually something minor like an incompatible plugin that can be identified and rectified relatively easily using the steps outlined above.

While the 500 error is undoubtedly annoying, it‘s not the end of the world. Stay calm, work through the troubleshooting steps methodically, and don‘t be afraid to ask for help if you get stuck. By following WordPress security and performance best practices, you can keep those 500 errors to a minimum and enjoy a stable, reliable WordPress website.