Click green flag to start, then click CPS TESTER button. Click the circle as much as you can, then it will show how much clicks you make in a second. After it would represent how fast you could click like a animal. After there is a retry button and the process goes on and on again! :D It does show the cps but very generally (like just the ones and tens) -Update 1- 1. The number at the end is your general cps.
The number before (since this is a 5 sec cps test) is an accurate cps while the after number is more general