When can my baby sleep without a hat or without being swaddled?

At home, I do not think there's any need to put hat. I stopped swaddling my baby when she was 3 or 4 months old. And to top swaddling the baby is such an effortless thing that you wouldn't even come to know how and whine happened. Check this out. http://www.wikihow.com/Transition-from-Swaddling