The 503 Service Unavailable error is a web server error. This means that it usually has nothing to do with what you did. It also has little to do with the web browser application you are using. It simply describes a situation where your server cannot (the server is temporarily unable) to process your request at some point.

It’s important to note that this error message also comes in different forms, so you don’t get confused. Here are some of the HTTP status code examples:

  • Error 503 Service Unavailable
  • HTTP / 1.1 Service Unavailable
  • 503 Service Unavailable
  • Service Unavailable – DNS (Domain Name Server) Failure
  • HTTP 503


The most common causes of the error

Common causes of WordPress temporary service unavailability error are things like server maintenance and high website traffic (too high for your hosting provider package, for example).

Like any other modern system, servers require regular checks. This includes software updates, hardware tests, upgrades, and so on. It usually takes less than a couple of hours, but it still often returns a 503 error code.

In addition, an unreachable external server or a misconfiguration of the DNS server could be the cause of this problem.

PHP scripts: often the inability of a plugin or theme to load when requested by the server returns a 503 error;

Custom Scripts: Newly added custom scripts to your WordPress site could be another possible cause;

Distributed Denial of Service (DDoS) Attacks: If your site is the victim of a DDoS attack that floods your site with traffic, thus making it inaccessible due to overwhelming traffic.

How to Fix 503 Service Unavailable Error?

First, move your WordPress site to a reliable hosting company that can provide you with a reliable and secure service. Siteground is a one-stop web hosting provider that I recommend for hosting your WordPress blogs or websites.

If the probable cause of the Error 503 service being unavailable is a WordPress issue, here are some solutions you can try to fix the issue:

  1. Disable Plugins

Like most WordPress site owners, you are probably using multiple plugins, which can lead to incompatibility issues. By disabling your plugins and then reactivating them one by one, checking if your WordPress site is running, you will come across the plugin that caused this issue.

You will need to use an FTP client like FileZilla, which means that you will need to look up your FTP credentials in order to be able to transfer files to and from your server.

Once you’ve managed to log into your server from FileZilla, follow these steps to disable plugins:

  • Find and open your WordPress root folder (www or public_html)
  • Go to the wp-content directory
  • Right click on the plugins folder and select the “rename” option
  • Rename the plugins directory to plugins-deactivated

This will deactivate all your plugins and you will be able to access your WordPress site if the 503 error was caused by a plugin incompatibility issue.

Then you will need to go back to FileZilla, access the wp-content folder, and rename your plugins-deactivated folder to its original name. This will not reactivate your plugins, it will only force WordPress to recognize them, so you can reactivate them one by one in your WordPress dashboard until you find the culprit. When you have done that, return to FileZilla and remove the corresponding plugin in the wp-content / plugins directory.

  1. Disable WordPress theme

If the plugin incompatibility issue was not the cause of the error, your WordPress theme might be the culprit. You will also have to rely on an FTP client here to get the job done.

Open the wp-content / themes directory and find your active theme folder, then just like you renamed the plugins folder , do the same for the themes folder, i.e. mytheme-deactivated , and try to access your site. If you succeed, and at this point you see the default WordPress theme instead of your old theme, it means that the 503 Service Unavailable error was caused by your theme.

Make sure you download the latest version of your theme from the developer, and if the problem still persists, even if you are using the latest version of your theme and the developer cannot provide a fix, you will unfortunately have to find another theme.

  1. Debugging custom code

If neither plugins nor your theme were causing the error, it’s time to enable the debug feature in WordPress to see if any of your custom code additions were causing the problem.

To enable the debug feature, follow these steps:

  • Go to FileZilla and find your WordPress root folder
  • Look for the wp-config.php file
  • Right click on it, then select View / Edit, which will open the file in your text editor
  • Find the line “That’s all, stop editing! Happy blogging “
  • Add the following code above this line: @ini_set (‘display_errors’, 1)

Or, you can open wp-config.php , find the line define (‘WP_DEBUG’, false) ; and change false to true.

Save changes and close the file. Reload the site and you will see an error log message.

This will enable the debugging feature and display an error message, usually detailing the file and even the specific line of code that is breaking. This way you can find the file using FTP and make the necessary changes to get everything back to normal.

The WordPress debugging feature is disabled by default for security reasons, so if you’re done making changes, we recommend that you disable it.

  1. More options

Try adding the following code to functions.php (disable autosave post changes):add_action ( ‘init’ , ‘stop_heartbeat’ , 1 ) ;function stop_heartbeat () { wp_deregister_script ( ‘heartbeat’ ) ;}

If, after adding and reloading the site, the error disappeared, then this was the reason for its occurrence. If not, don’t forget to remove the code from functions.php

Also, try limiting the frequency of search engine bots crawling. For google it can be done here:

  1. Contact your web host

If you suspect you are undergoing a DDoS attack, or you have a legitimate spike in traffic that is causing an downtime issue, contact your web host’s support team as they can assess the situation and suggest a solution.

Your web host may recommend that you upgrade your hosting plan, or they may temporarily scale your resources to be able to handle traffic inflows, or implement DDoS mitigation mechanisms if the issue is caused by a DDoS attack.

If your web host is inactive in helping you deal with this problem, you might consider migrating to another hosting company.

What to do and how to remove the 503 error from the user side?

If you don’t have access to the server interface, there is little you can do to fix it directly. But fear not, you can still try the following solutions.

  1. Let’s start with the most important thing – refresh the page

As with most WordPress site problems, the simplest solution is usually the best. “F5” (or Ctrl + R) on your keyboard or right-clicking and the “reload” option will refresh your page. You can also copy the link from the address bar, open a new tab, paste it and hit enter.

  1. Reboot your router and modem

If the first step doesn’t fix the problem, try restarting your router and modem. This will create new connections that use different ports than before, and possibly fix the bug. How to do it:

  • Take your router.
  • Find where its cable starts and unplug it.
  • Do the same for your modem.
  • Wait 30 seconds.
  • Connect the cable back to both devices.
  • Again, wait about 50 seconds.
  •  Try to see if the problem is gone.

You can also try restarting your computer in the process, it certainly won’t hurt.

  1. Wait a bit

The error itself states that this problem is temporary. Most likely, it will improve in a couple of hours at the most. If you’re in no rush, give the server some time to complete maintenance or free up traffic. In addition, some applications often give approximate or specific time stamps so you can know when you can return to your normal workflow. They use the so-called Response-After HTTP header.

  1. Ask for help

If the steps above do not fix the problem, you should contact a professional. You can also contact your hosting provider. Someone on their team can change the server settings or fix the problem in some other way.

If you have access to the server:

Review the log files

As you probably know, most applications and systems keep detailed records of what they do. This includes timestamps, locations, connection ports, and a lot of other important information. So, the first step in this process, of course, should be to verify them. They can give you some idea of ​​when and why the error occurred. (You can of course use them to diagnose other problems as well.) If you’re not sure where the logs are, use Google to find their location for your specific model.

Reboot server

Now that we know a little about the cause, let’s do the most common fix – reboot. Find the reboot option in your server’s interface and activate it. If your page or application is hosted on multiple servers, do it for everyone. The 503 error might just be a “jam” somewhere in your server chain, so it could very well be a “cure”. Wait a couple of minutes. If that didn’t fix the problem, go to the next step.

Check your server for connection problems

Nowadays, more and more often, a web application is spread across multiple servers. One server can store content, another can do some computation, and so on. This opens up the possibility of a problem only occurring on a specific server in the chain (for example, it might be down or unavailable for some reason) which is why you should check all connections to make sure you are not missing anything.

Check your firewall settings

Like your computer and all devices connected to the internet, servers have their own firewalls. This is their main defense against malicious internet traffic. The firewall creates a rule for what can and cannot pass through your server. This is a great way to stop bad intentions, but sometimes it also creates unusual problems. One of these problems is called false positive. If not configured correctly, the firewall can tend to drop otherwise perfectly normal traffic. This results in 503, so this is definitely the next place to look for the cause.

If you are not sure which is the best setting for you, or consult a professional.

See if there is service in the session

Every system must be constantly updated to stay in perfect condition. As we said, this process consists of software and hardware updates, checks, and so on. The servers are in most cases configured to perform maintenance automatically, hence this may be the reason you are getting 503 errors.

Go to your server dashboard and check your update settings. You don’t need to do anything here, but changing the update frequency might help if the problem persists. However, the default configuration is usually best for new users.

You can also put everything in manual mode, but we would not recommend this for beginners. The reason for this is that updates increase security and keep things under control, so forgetting to update puts your system at risk.


As your site gets more traffic, you may notice that it will slow down, or you may directly face downtime issues.

Thus, we recommend that you upgrade your hosting plan to a better one to avoid such problems.

You may also consider integrating a Content Delivery Network (CDN) with your WordPress site, which will reduce the load on your server and make your site faster and more secure.

Error 503 unavailable service may seem like a tough nut to crack at first, but if you follow our instructions step by step, you should be able to fix it quickly.

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