How to Fix “503 Service Unavailable” WordPress Error (Quick Solution)

The “503 Service Unavailable” error means your website cannot answer requests at the moment. On a WordPress site, the cause is often a plugin, the theme or too many requests to the server. In my video, the cause was an outdated theme. Below I show you how I found it and fixed it step by step, plus other fixes you can try.

In this article

1. What is the HTTP 503 Service Unavailable error?
2. What causes an HTTP 503 error?
3. How I fixed the 503 error on my WordPress site
   1. 1. Check if the server itself works
   2. 2. Disable all plugins
   3. 3. Check your theme
   4. 4. Update your theme
4. More fixes to try
5. 503 error variations
6. Seeing a 503 error on someone else’s website?

What is the HTTP 503 Service Unavailable error?

The HTTP 503 Service Unavailable error means that a website cannot be reached at the moment because the server is not ready to handle the request. This can happen because the server is too busy, it is under maintenance, or something else is wrong that needs a closer look.

What causes an HTTP 503 error?

These are the most common reasons why a server temporarily cannot handle a request:

• A high number of requests is being sent to the server, and they use up all the available resources.
• The server has technical problems or maintenance work.
• The server is under a Denial of Service (DDoS) attack.
• Other technical issues trigger the error, like problems with your WordPress plugins or theme.

One reason I see often: a script on the website, for example from malware or an outdated theme or plugin, sends too many requests. The hosting provider then stops the requests to protect the server, as if it were an attack.

How I fixed the 503 error on my WordPress site

You need access to your hosting control panel. I use the File Manager in cPanel, but an FTP program works too.

1. Check if the server itself works

1. Log in to cPanel and open File Manager.
2. Open the public_html folder (the folder of your website).
3. Do a quick test to see if the server answers. In the video, I temporarily replaced the content of index.php with a line of text, saved it and refreshed the website.
4. If your text shows up in the browser, the server and the hosting work fine, and the problem is inside WordPress.
5. Put the original content of index.php back and save it. The 503 error comes back, so now you know you have to look at WordPress.

Warning: if you do this test, copy the original content of index.php to a text file first, so you can paste it back. A safer option is to upload a small file, for example test.html, and open yourdomain.com/test.html in your browser.

2. Disable all plugins

1. In File Manager, go to public_html > wp-content.
2. Rename the plugins folder, for example to plugins-off. WordPress can no longer load any plugin.
3. Refresh your website.
4. If the website works now, one of your plugins causes the error. Rename the folder back to plugins and reactivate your plugins one by one to find the bad one.
5. If you still see the 503 error, rename the folder back to plugins and continue with the theme.

In my case, nothing changed with the plugins disabled, so the plugins were not the problem.

3. Check your theme

1. In wp-content, rename the themes folder (or the folder of your active theme).
2. Refresh your website.
3. If the 503 error disappears, your theme is the problem. On my site, I got a blank white page instead of the error, which showed me that the theme was the cause.
4. Rename the folder back to its original name.

4. Update your theme

1. Open your theme folder and open the file style.css. The version of the theme is written at the top. My theme was version 1.1.9, from April 2022. It had not been updated for a year.
2. Download the latest version of your theme from the theme developer. For my theme, that was version 1.3.
3. In File Manager, upload the theme ZIP file to wp-content > themes.
4. Extract it so that it replaces the old theme files. If you use a child theme, update it the same way.
5. Refresh your website. In my case, the website was back online right away.

Tip: keep WordPress, your theme and your plugins up to date. An outdated website can stop working, like mine did. If fixing the 503 error is too hard for you, contact your hosting provider or chat with their support, and explain the problem. They can usually fix it or tell you what causes it.

More fixes to try

Here is the full list of quick solutions for a WordPress 503 error:

• Deactivate your plugins and switch your theme, as shown above.
• Temporarily disable your Content Delivery Network (CDN): if you use a CDN or a proxy like Cloudflare, pause it for your site. If the error disappears, the problem is in the CDN settings and not on your server.
• Limit the WordPress Heartbeat API: the Heartbeat API lets the WordPress dashboard talk to the server in the background, for example for autosave. With many open admin tabs, it can send a lot of requests. A plugin like Heartbeat Control lets you reduce or disable it.
• Increase your server’s resources: if your website gets more visitors than your hosting plan can handle, upgrade your plan or ask your host for more resources.
• Review your logs and enable WP_DEBUG: in cPanel, check the error log (in Metrics > Errors). You can also turn on the WordPress debug log in the wp-config.php file, as explained below.

To turn on the debug log, add these lines to wp-config.php, above the line that starts with /* That's all, stop editing!:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

WordPress then writes errors to the file wp-content/debug.log. When you have found the problem, set WP_DEBUG back to false. More details are in the official WordPress debugging guide.

503 error variations

The 503 error can show up in many ways. Almost every variation includes the code 503, so it is easy to recognize. Depending on your server and your browser, you may see:

• 503 Service Unavailable
• 503 Service Temporarily Unavailable
• HTTP Server Error 503
• HTTP Error 503
• Error 503 Service Unavailable
• The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Whatever the message looks like, if it is your website, fix it fast before it affects your visitors.

Seeing a 503 error on someone else’s website?

If you only visit the website and it is not yours, the problem is usually on their server. A 503 error can be frustrating, especially in the middle of an important task, but there are a few things you can try:

1. Refresh the page. Press the refresh button or F5. This quick step sometimes solves the problem.
2. Wait and try again later. The error often appears when the server is overloaded, and it can take some time until the website is available again. You can also check the website’s social media or status page for updates.
3. Clear your browser cache. Your browser stores temporary files and cookies to load websites faster, but sometimes these files cause errors. Go to your browser settings and clear the cache and cookies.
4. Check your internet connection. Make sure your connection is stable, and try restarting your modem or router.
5. Contact the website’s support team. If nothing else works, they can tell you why the website is unavailable.

In most cases, a 503 error is temporary. For website owners, the steps above usually bring the site back online quickly.