How do you check your hosting quality?

[russ111]

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