How to Debug and Fix 503 Service Unavailable Error in WordPress

Came across a white screen with a “503 Service Unavailable” error message on your WordPress website? In this tutorial, we will show you how to debug and fix the 503 WordPress error.

How to Fix 503 Service Unavailable Error in WordPress?

There a number of reasons why this error could occur. We’ll go over each of the causes and provide you with solutions on how to fix the 503 Service Unavailable issue.

WordPress Plugin Bug

If you’ve encountered the HTTP 503 error after installing or updating a particular WordPress plugin, you might have found the culprit. Just delete your most recently installed plugin to solve the issue.

However, if you don’t know which plugin is causing the service unavailable error, you should diagnose the root of the problem by disabling all plugins and enabling them one by one.

Deactivating All WordPress Plugins

You can remove your WordPress plugins through the File Manager on your hosting control panel. In this example, we’ll be using hPanel:

1. Access the hPanel, then head over to File Manager under the Files section.

2. Once you’ve access to your files, select the public_html -> wp-content folder.
3. Locate the plugins folder and right-click.
4. Rename it into plugins_disable to deactivate all plugins at once.

5. Rename the plugins_disable folder back to its original name — plugins.
6. Refresh your WordPress site and access your wp-admin area.

If the HTTP 503 error is gone, a specific might be the problem. All you have to do is identify and delete the problematic plugin from your admin dashboard by following these steps:

1. Log in to your WordPress dashboard and head over to the Plugins -> Installed Plugins section.

2. Activate the plugin one by one and reload your site each time to pinpoint the buggy plugin.
   

   NOTE: If the 503 Service Unavailable error appears again after you’ve just activated a certain plugin, it’s clear that the plugin is the culprit.

3. Delete the plugin by accessing the public_html/wp-content/plugins folder from your File Manager.
4. In this example, our culprit is in the disable-comment folder — right-click and select delete from the drop-down menu.

Once you’ve performed all of the steps above, the error 503 Service Unavailable should disappear, and you can reaccess your website.

Faulty WordPress Theme

If your plugins are not causing the 503 Service Unavailable error, your theme might be the root problem. Especially if you got the HTTP error 503 in WordPress after installing a new theme.

To tackle this issue, switch to a default WordPress theme, such as the Twenty Nineteen, or Twenty Twenty themes

Deactivating a WordPress Theme Using the File Manager

Disabling your WordPress theme using File Manager is similar to deactivating your plugins.

1. Under the Files section on you hPanel, access File Manager -> public_html -> wp-content folder.
2. Find the themes folder, and rename your currently used theme. Let’s say you’re activating my-theme —right-click on the folder and rename it into my-theme-off. Your theme will switch automatically to the default WordPress theme.

3. Once that is done, you can reload your website to see if it’s working.

Deactivating WordPress Theme Through phpMyAdmin

If you don’t remember the name of the theme that you’re using, there’s another way to deactivate it. Here, we’ll be changing to the Twenty Seventeen theme:

1. Open your hPanel, then go to phpMyAdmin under the Databases section. Select Enter phpMyAdmin option.

2. Find the template and stylesheet values within the wp_options table.
3. Your currently used theme name is on the option_value column. Double-click on the name, and rename it to twentyseventeen.
4. Reload your site once you’re done to view your changes.
   

   NOTE: If the 503 WordPress error disappears after deactivating your currently used theme, try to update the theme to the latest version. Otherwise, it’s better to get a different theme.

Custom PHP Code Problem

If the 503 Service Unavailable error persists, there might be a broken custom PHP code snippet somewhere on your website. To find out if that might the problem, try debugging your site to diagnose and fix the error.

Enable WP_DEBUG

Since the HTTP 503 error often locks you out of your admin area, activate the WP_DEBUG mode from your File Manager, so you can check the error logs:

1. Go to your hPanel, and navigate to File Manager -> public_html folder.
2. Locate and open the wp-config.php file.
3. Scroll down and add the following code right before the line /*That’s all, stop editing! Happy blogging.*/:

   define ('WP_DEBUG', true);
   define ('WP_DEBUG_LOG', true);
   define ('WP_DEBUG_DISPLAY', false);
   @ini_set ('display_errors', 0);

4. Once you’re done, click Save & Close.
   

   IMPORTANT: If you’ve set a WP_DEBUG line within your wp-config.php file, activate it by changing the value from false to true.

5. Refresh your website, and it will showcase the error logs message.
   

   NOTE: You can see the error logs by accessing the /public_html/error_log file from your File Manager as well.

Server Related Issue

If the methods above still yield no result, the problem could lie in your web server. You can try these three server-side methods to solve the 503 Service Unavailable error in WordPress.

Limit WordPress Heartbeat

WordPress Heartbeat is a built-in API that allows your site to have an autosaving post feature. This functionality consumes your server resources, but you can limit it with the Heartbeat Control WordPress plugin or disable it altogether.

To determine if WordPress Heartbeat is the cause of the 503 Service Temporarily Unavailable error on your WordPress site, add the following code to your theme’s functions.php file right after the opening <?php tag:

add_action('init', 'stop_heartbeat', 1);
function stop_heartbeat(){
wp_deregister_script('heartbeat');
}

Once you’ve saved your changes, refresh your website and see if the error disappears. If that didn’t fix the error, then the WordPress Heartbeat is not the root cause of the problem. Before you continue, don’t forget to remove the code from your functions.php file.

Limit Googlebot Crawl Rate

Google and other search engines crawl your site to index your content — they visit your website regularly to gather content and determine other ranking metrics.

This crawling process can take a toll on your server resources. Consequently, it may slow down your site and cause the HTTP error 503.

Fortunately, once you’ve integrated your site to the Google Search Console, you can limit the maximum crawl rate. In order to do so from the crawl rate settings page, or request Google to limit your site crawl rate.

Increase Server Resources

If you’re getting the error 503 Service Unavailable message, check your Google Analytics page. If you’re getting more traffic than usual, you’re definitely short of server resources.

However, if you don’t have the extra traffic but still see the 503 error in WordPress, your problem might be an inadequate server memory.

What Is 503 Service Unavailable Error in WordPress?

503 Service Unavailable error means that your WordPress site is live, but the server cannot be reached because of a present problem. Additionally, it makes both your front end and admin dashboard inaccessible.

Depending on the server configuration, the WordPress error can be displayed differently. For example, you can see these error codes instead:

•     503 Service Unavailable
•     Http/1.1 Service Unavailable
•     HTTP Server Error 503
•     503 Error
•     HTTP 503
•     HTTP Error 503

The causes of it may vary — from faulty plugins or themes, a broken custom PHP script, to server-side issues.

Conclusion

The 503 Service Unavailable is a common error when your front end and back end area will not show your content. This is mostly caused by faulty WordPress plugins or themes, but other reasons occur as well.

Here’s a short recap on how to detect and solve the errors 503 in the future:

• Deactivating your WordPress plugins, then activating them one by one
• Disabling your current WordPress theme by going back to a default one
• Enabling WP_DEBUG mode
• Detecting and fixing server-related issues

Good luck and if you have any questions, drop a comment below.