How do you check your hosting quality?

[naba_dajani]

I check my site with Google PageSpeed Insights. I am checking during the middle of night when there is almost no traffic so I know there is no effect of server load. At least from my site.
I see big difference from test to test. Even between mobile and desktop in single test.
Score goes from 35 to 90 so I know web site is optimized for SEO since I get 90.
I know Google ads and other scripts can cause problems but I postpone adsbygoogle.js load and I have plugins for async load.I use Wordpress.

What would be good tool to check server response and server metrics?

Thank you

Jmeter can be used for Load and performance testing on the target application.