To check whether Speed Kit is active, first check whether the service worker is installed on your site:
1.) Open your website in the Chrome Browser.
2.) Press F12 to open the developer tools.
3.) Navigate to the tab "Application" and select "Service Workers on the left side.
There you should see an entry with your sites url as title (and usually "sw.js"/"speed-kit-sw.js" as Source).
Now you know that Speed Kit is installed, but you still need to check whether it's working and your content is successfully being accelerated by our servers:
4.) Inside the developer tools open the "Network" tab.
5.) Press F5 to reload the page while recording network activity. You should see the list fill with entries.
6.) Check for requests that show "(from Service Worker)" in the Column "Size" - these are the requests accelerated by Speed Kit.
Read about it in more detail here.
Follow our video guide on how you can see the speedup yourself here.