aceess speed issue over the internet

how do i actually check for it as to what s causing the issue

whether its my code , logic or the server hardware issue or network issue or  bandwidth

the thing is the result which is seen now the output thats received after i am done with the page

i mean i need to know or make a test as to confirm that my code or the web pages are not causing the speed issue but the server hardware or anything that casuing the issue

so anymeans by which this can be proved as the resultant web application currently give a very bad performance