You can check Server Response time using Pingdom (it also helps you track website performance and downtime)
Or, you can check the response time manually from the command prompt.
Type "ping" followed by your website IP address
It will show you the time server used to respond
If your server response time is low, you should look for another fast web hosting provider.
Also, check the content delivery network (CDN) location.
It is preferable to use the CDN nearest to your target audience; by reducing the distance between your web hosting server and website visitors, you can improve latency issues which will ultimately help you reduce overall response time.