The ‘503 Service Unavailable’ error is one of the most popular error messages on the World Wide Web. This error happens when a web server is temporarily unavailable to handle the request. It could be the web server that you are trying to access directly or another server that web server is trying to access it. The most common reasons for this error is either the server is overwhelmed with the requests or due to maintenance performed on it.

503 is one of the HTTP Codes that informs any server-side error which prevents the requests from being processed. The message ‘Service Unavailable’ informs the client that the service is temporarily not available.

Reasons for 503 Service Unavailable Error:

When the server could not deliver the requested resources at the time of the requests made by the client, then the mentioned error will occur. It is different from 500 Internal Server Error. The possible reasons for 503 Service Unavailable Error are mentioned below

1. Inadequate Server Resources:

In a multiple domain hosting environment, the server resources such as disk space, memory limit, CPU usage, I/O would be divided among multiple websites hosted in the server. Every cPanel account will be limited with a certain usage of resources so any increase in resource usage can cause this type of error.

2. Misconfiguration of Web Server:

The web servers have a common configuration setting by default. The default settings may work fine with the low density and low traffic websites which may not be suitable for high traffic websites. So, the server configuration settings such as memory limits, connection timeouts should be fine-tuned in the server. If the server resources are not tuned fine, then it may cause the error.

3. High Web Traffic due to attacks:

The website access can vary from time to time according to the peak business hours. Sometimes, the website access can increase due to bots, attacks or other hacking attempts which drains the server resources and leads to the error.

4. Buggy Applications or Server Software:

The applications like WordPress contains a huge set of plugins which are installed by website owners for various features. If any code or plugin has a bug, then this type of error may occur so that website becomes unavailable for the visitors. And also, if the server software such as the database, PHP, etc are not fine-tuned for optimal performance, then it may cause the error.

5. Incorrect DNS Configuration:

In rare cases, the incorrect DNS configuration can cause the error. It happens when the selected DNS server itself has temporary problems in it.

Solution to Fix ‘503 Service Unavailable’ Error:

If your website is down due to this error, it can be fixed easily with the below solutions.

  1. Check the server resources:

If your website is facing this type of error, log in to your control panel and check the server resources like disk space, CPU and memory usage. If any of the resources are consumed fully, upgrade and then check which will be resolved.

2. Update the software regularly:

If any malicious spam or software is triggering the error, contact your hosting provider to detect them and work to resolve the issue. It is always suggested to update the software with recent updates as outdated applications can cause vulnerabilities.

3. Fix Programming Errors:

If any CMS like WordPress is incorrectly programmed, then it may cause 503 error due to longer loading time. Once the server resources and account usage are checked, check the problem causing plugins and deactivate them if needed.

The mentioned error ‘503 service unavailable’ can happen on both the server and client end. We hope that the above solution will help you to fix the error.  If the error persists, contact your hosting provider, they can able to find the cause of the error easily. Like us on Facebook and Twitter and subscribe to our youtube channel for video tutorials.