Hi Altan.. Although your question is not specific.
But i conclude that you need to test the performance of your website.
There are many online tool available to test your web page performance
you have multiple option to select your required performance and even it generate customized white report for your client.
this check page speed and is free
this also check page speed and is free.
Hope this help you folks!... do let us know and accept the solution if you are satisfied