503 errors are usually caused by a conflict (a plugin, theme, or script that conflicts with another plugin/script), excessive resource usage, or CDN issues. The error message is vague; often, these errors are not related to the web server.
Applies To:
This guide applies to Web Hosting, Semi Dedicated Hosting, Reseller Hosting, and managed servers.
Error Message
The exact error might be different on your website:
"503
Service Unavailable
The server is temporarily busy, try again later!"
Or,
"503
The server is too busy to handle your request.
Please wait a few minutes and try again."
Step 1: Check CDN
If you are getting a 503 error and using Cloudflare, Quic.cloud, or any other CDN, refer to the following guide:
Fix 503 errors when using Cloudflare
Step 2: Check Conflict with LiteSpeed Cache
When a plugin includes features that overlap with LiteSpeed Cache, this can cause a conflict and trigger a 503 error. Please refer to the following guide to check and fix a conflict:
How to check plugin conflict with LiteSpeed Cache?
Step 3: Check Resource Usage
If you are getting a 503 error, check the resource usage for CPU, Physical Memory, I/O Usage, IOPS, Entry Processes, and Number of Processes:
- Log in to cPanel.
- Your average usage is listed under the "Statistics" section on the right sidebar in cPanel.
- If any of the above items are above 90%, you might be hitting resource limits, which in turn triggers the error.
- You can also view past resource usage:
How to view resource usage?
In many cases, resource usage can be reduced by optimizing the website, plugins, and themes.
If your resource usage is high, try to reduce the resource consumption.
If your resource usage remains high after applying the suggestions in the guide above, contact us for a closer look.
If resource usage is not high, proceed to the next step.
Step 4: Run a PHP Info Page
- Go to cPanel > File Manager.
- Navigate to the
public_htmldirectory.public_htmlis the root directory of your primary domain.
The root directory is different for other domains and subdomains. You can view the root directories in cPanel > Domains. - Click "+ File" from the top menu and enter
phpinfo.phpin "New File Name". - Select the
phpinfo.phpfile and click "Edit" from the top menu. - Type in the following lines in the file:
<?phpecho phpinfo();?> - Click "Save Changes".
- Visit
https://yourdomain.com/phpinfo.phpto view the page.
Replaceyourdomain.comwith your actual domain. - This is a very basic PHP page that should not throw any 503 error.
If you do not get any error, there is no issue running PHP on your account.
If you get any error, contact us.
If you do not get any error, proceed to the next step.
Step 5: Inspect Error Log
A misconfigured, malformed, or incompatible plugin, theme, or script can cause the error. View the PHP errors to find out what is causing them and disable or update the offending plugin/theme/script:
How to view PHP errors?
If that does not solve the error, contact the devs of the offending plugin, theme, or PHP script for support.
