I took a small online dumb test. The results said that I am smarter than 6.31% of the world. Is this

I am not sure what a "dumb test" is, but I am sure that anything you find online is intended to be entertaining rather than revealing. According to online IQ tests, everybody is at least 20 points above everybody else.

Yeah, the two above are completely accurate. Quite frankly I can't bring myself to believe that anyone is smarter than x% of the world, simply because no test can cover every topic in the world. For example if I were to take a test to test your philosophical knowledge and my "Rival" in the test didn't know the first thing about philosophy, I'd likely be "smarter" than him. However, if said rival is extremely skilled with something like welding and I'm told to take a test in the field of welding with him, odds are he'd been seen as much "Smarter" than me, due to the fact that we are each intelligent in our own fields, so an overall general test of your intelligence just can't exist properly.