Extreme lag!

I just bought a realm for 2 and i am very disappointed. Each time the realm keep lagging. At first i thought it was my internet connection but my friend too could experience it. I had stop and relauch the realm but the lag was still here and when i tried to replace the world with my local world it said error.
I don't know if that lag is due to the realm type that i bought or it's just the realm.