You can test the server response time of a web hosting provider's website by using online tools like Pingdom, GTmetrix, or Google PageSpeed Insights. These tools can give you a good indication of the website's performance, including server response time.

Additionally, it's worth noting that server response time can vary depending on factors such as server load, network congestion, and the location of the user accessing the website. Therefore, it's important to keep in mind that a web hosting provider's server response time may not always be consistent.