Server side errors occur when a failure to render a page falls on the server.
A large spike in 500 or 503 errors could indicate the inability for the site’s web hosting and server to manage the requirements of the site, resulting in downtime for visitors.
How to check for server side errors
- In Google Search Console navigate to Coverage > Errors
You will see a list of 50x errors occurring on the site
OR - Use Screaming Frog