How to Fix 500 Internal Server Errors in WordPress

With over 810 million WordPress websites populating the World Wide Web, WordPress remains the most popular web hosting platform in existence. But while it’s true that WordPress is a quality and reliable hosting provider, that doesn’t mean that WordPress sites are immune to errors.

One type of error that WordPress websites commonly encounter is 500 internal server errors. These errors indicate that something has gone wrong with the server hosting your website, and they can cause some serious issues if they aren’t resolved.

In this guide, we’ll cover everything you need to know to troubleshoot and fix WordPress 500 errors, including their common causes, troubleshooting steps, and best practices for preventing future errors.

What is the WordPress 500 error?

A WordPress 500 internal server error (also called an HTTP error 500 in WordPress) is a general server-side error that indicates something has gone wrong on your web hosting server, but the exact cause is not specified. Because it is a general “catch-all” error, it can be difficult to diagnose and often requires step-by-step troubleshooting to identify the root cause.

Unlike more specific WordPress errors, a 500 error can affect both the front end of your WordPress site and the WordPress admin (wp-admin), including login pages and the dashboard. In some cases, the error may only affect the WordPress login page or wp-admin dashboard, often due to plugin conflicts, theme issues, or server configuration problems.

Before troubleshooting, it’s important to create a full backup of your WordPress website, including your files and database, so you can safely restore your site if needed.

Possible impact

A WordPress 500 internal server error can have serious consequences if it isn’t resolved quickly. These errors can impact your website in several ways:

• Poor user experience: Pages fail to load, making your site appear broken or unreliable to visitors
• SEO impact: Search engines may struggle to crawl your site, leading to indexing issues and potential drops in rankings
• Reduced visibility: Important pages may be removed from search results if they consistently return errors
• Higher bounce rates: Users are more likely to leave immediately after encountering an error
• Lost conversions: Interruptions during key actions (forms, purchases, logins) can reduce leads and revenue
• Decreased trust: Repeated errors can damage user confidence in your website or brand

Because of these risks, it’s important to identify and fix 500 errors as quickly as possible to maintain both performance and search visibility.

What are common causes of WordPress 500 errors?

A 500 error does not point to a specific issue and is usually caused by one of the following:

• Corrupted .htaccess file: This file controls many important aspects of server behavior, and if it gets corrupted or misconfigured, it can lead to a 500 error.
• PHP memory limit issues: When your site exceeds the allocated PHP memory limit, it can result in an internal server error due to insufficient resources.
• PHP version compatibility issues: Conflicts between your PHP version and installed plugins or themes can lead to 500 internal server errors.
• Problems with WordPress plugins: Faulty, incompatible, or poorly coded WordPress plugins can cause conflicts that lead to 500 errors.
• Syntax errors in PHP files: Even a small coding mistake in a PHP file can cause a server error and trigger a 500 response.
• Corrupted core WordPress files: Corruption in the WordPress core files—often due to malware, file transfer issues, or incomplete installations—can cause 500 errors.
• Failed WordPress updates: Interrupted updates to WordPress core, plugins, or themes can leave files incomplete and trigger a 500 internal server error, especially during updates in the WordPress admin (wp-admin).
• Issues with file permissions: Incorrect file and directory permissions can prevent scripts from running properly, resulting in an internal server error.
• Browser cache problems: Sometimes, a 500 error may be caused by issues with the browser cache, which can be resolved by clearing the cache.

Step-by-step troubleshooting guide

With so many different issues that are capable of causing these errors, it is essential for website owners and support teams to follow the right troubleshooting steps. If you are encountering a 500 internal server error message, here are the steps you should follow to diagnose and fix the issue:

1. Backup WordPress site

Before you get started making changes to your WordPress site, be sure to do a complete backup first. This should include backing up the database and all of your files. That way, if anything goes wrong during the troubleshooting process, you can easily restore your website to its previous version.

2. Clear browser cache and refresh

Sometimes, cached files in your browser can cause 500 errors. Since this is a simple issue to fix, it’s a good first step after backing up your site. To check, clear your browser cache and refresh the page to ensure you're loading the latest version from the server.

In Chrome, for example, open the three-dot menu, go to Settings > Privacy and security > Clear browsing data, clear cached files, then refresh the page. While this step addresses front-end issues, most 500 errors originate from server-side problems.

3. Check the .htaccess file

The .htaccess file plays a critical role in configuring how your server handles requests. If this file is corrupted or incorrectly configured, it can lead to a 500 error. Misconfigured redirects in the .htaccess file can also trigger 500 errors if rules conflict or create loops. To check if this is what’s causing the error, you can use an FTP client (Filezilla) or cPanel's File Manager to access the .htaccess file and then rename it (something like .htaccess_old will work fine). This action will effectively disable the file.

If this resolves the 500 error, you will then need to regenerate the .htaccess file. You can do this by navigating to the Permalinks settings page in your WordPress admin dashboard and clicking "Save Changes" to regenerate the file automatically.

4. Increase PHP memory limit

Inadequate PHP memory is a common cause of 500 errors, especially on sites with heavy plugin usage or complex themes. To increase the PHP memory limit, you’ll need to edit the wp-config.php file located in your WordPress root directory.

Once you’ve accessed this file, add the following code:

define('WP_MEMORY_LIMIT', '256M');

Replace ‘256M’ with the amount of memory you want to allocate. If you’re unsure how much you need, you can contact your hosting provider for assistance. In some cases, server resource limits set by your hosting provider (such as CPU or process limits) can also contribute to 500 errors.

5. Deactivate all plugins

Faulty or incompatible plugins are often the culprit behind WordPress 500 errors. The simplest way to determine if a plugin is causing the error is to deactivate all your plugins at once. You can do this from the WordPress admin dashboard by navigating to the Plugins section, selecting all plugins, and choosing "Deactivate" from the Bulk Actions dropdown menu. If this resolves the error, you will then need to reactivate your plugins one by one and test your site after each activation to see which one is causing the error.

If you’re unable to access the WordPress dashboard, you can also deactivate plugins by renaming the plugins folder inside the wp-content directory via FTP.

6. Switch to the default WordPress theme

Sometimes, the active theme you're using may not be compatible with certain plugins or the version of WordPress you’re using. To test if your theme is causing the 500 error, try switching to a default WordPress theme (like Twenty Twenty-One).

You can change your theme from the WordPress dashboard by navigating to Appearance > Themes, selecting a default theme, and activating it. If this fixes the 500 error, then you will need to either use a different theme or contact the theme developer for help.

7. Check file permissions

Incorrect file and directory permissions can prevent WordPress websites from functioning properly, resulting in a 500 internal server error. To verify and adjust file permissions, start by connecting to your server using cPanel or an FTP client. From there, you can check the permissions settings on both your files and directories.

Directories within your WordPress installation should typically have permissions set to 755, while files should be set to 644.

8. Enable WordPress debug mode

If you enable debug mode, it will provide you with more detailed error messages that can offer valuable information about what’s causing a 500 error. To enable debug mode, open your wp-config.php file located in the WordPress root directory and add the following lines of code:

define('WP_DEBUG', true);

define('WP_DEBUG_LOG', true);

Once debug mode is enabled, you can then access the debug.log file for detailed error messages and warnings that may help you identify the root cause of the 500 error.

9. Re-upload core WordPress files

WordPress 500 errors are sometimes caused by core files of your WordPress installation that are corrupted or incomplete. To test if this is the issue, you can re-upload the core WordPress files from a fresh installation.

Obtain a clean copy of WordPress from wordpress.org, unzip the file on your computer, and use FTP or a file manager to upload the wp-admin and wp-includes directories directly to your server and overwrite your existing directories. This will ensure that all core WordPress files are intact and correctly configured, and will often fix the 500 errors.

10. Check for corrupted database

A corrupted WordPress database can cause 500 errors. Thankfully, WordPress provides a built-in database repair tool that you can use to diagnose and repair database issues. To access this tool, add the following line of code to your wp-config.php file:

define('WP_ALLOW_REPAIR', true);

Once you’ve done this, save the wp-config.php file and navigate to https://yoursite.com/wp-admin/... in your web browser. This page provides options to either repair the database or repair and optimize tables. Follow the instructions for preparing the database, then be sure to remove the define('WP_ALLOW_REPAIR', true) line once you’re done, as it can present a security vulnerability if left in place.

11. Review error logs

Website logs, and specifically server error logs, provide valuable information that you can use to pinpoint the cause of 500 errors. These logs are often the fastest way to identify the root cause of a 500 internal server error.

To access server error logs, you can use either your hosting control panel or FTP to navigate to the server's log directory. Look for entries related to the time and date when the 500 error occurred, and review any error messages, warnings, or stack traces provided in the logs, as they can provide clues about specific PHP or server-side issues causing the error.

Server-level issues in environments like Apache or Nginx can also trigger 500 errors if configurations are incorrect.

12. Consult hosting provider

If all else fails, you should contact your hosting provider for further assistance in fixing the error. A lot of times, 500 errors are caused by server issues on the hosting provider’s end. In these cases, they will be the only ones capable of fixing it.

When you contact your hosting provider’s support team, be sure to include detailed information about the issue, including any error messages or steps you've already taken to troubleshoot the problem.

Advanced WordPress security tips

It’s essential for WordPress website owners to know how to troubleshoot 500 errors—but preventing them from ever happening in the first place is even better. Here are a couple of advanced WordPress security tips to help you reduce the likelihood of 500 errors and other issues:

Check PHP version compatibility

WordPress regularly updates its software to leverage the latest PHP features and security enhancements. If you’re using an outdated PHP version, you may need to upgrade to the latest version in order to benefit from these performance improvements and security patches.

In some cases, the plugins or themes you’re using may not be compatible with the latest PHP version. In this instance, you may want to consider downgrading to a slightly older (but still supported) PHP version until plugins and themes are updated to support the latest PHP release.

Restore from backup

Regularly backing up your WordPress website is a major key to safeguarding it against data loss and security breaches. In the event of accidental data loss, hacking, or site malfunction, having a recent backup available will allow you to easily restore your website to its previous configuration.

With a security plan like SiteLock that includes website backups, you can even backup your WordPress website automatically.

Protect your WordPress site with SiteLock

If you want to avoid extended periods of website downtime, knowing how to troubleshoot and fix WordPress 500 errors is key. Preventing 500 errors and other performance/security issues is just as important, and there are a number of tools and best practices you can use to better protect your WordPress website.

At SiteLock, we offer a comprehensive suite of security tools and services that are designed specifically for WordPress websites, including WordPress malware removal services. To get started bolstering your website’s security and performance, be sure to check all that SiteLock has to offer!

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