Hi guys!
My Mac is running slow, even when I am surfing the web. Did anyone have such problem? How to fix it?
How old is your MacBook?
I normally fix that by suggesting not using a Mac. 
So many potential variables. How old is the mac, what OS are you on, what browser, could it be your network connection etc etc.
Is it slow when you turn internet off? I haven’t had speed issues with my mac but I know that some of my PCs were slower when internet was turned on. Granted the anti virus could’ve been a factor, goodness knows those programs take up so much processing power.