why is my firefox browser so slow?

I have a horrible experience using firefox as my personal browser well u could could say it's my. Default browser to this point but I just couldn't help myself to get annoyed on how slow it takes to load a site. After using firefox for couple of day it's fast but after some time it really became slower. I asked myself why? I thought of the extensions I've downloaded/enable or probably because of my wifi but no it wasn't my wifi or probably my extensions I tried in chrome it loads faster more efficient. I hope u guys fix this and improve the user experience.