I have a hard lump on my inner thigh thought it was a boil and had it about a month now. it is painless ?

Lymph node vs. cyst: Any skin and subcutaneous lesion heavy depend upon visual exam to be diagnosed correctly but two assumptions can be made from your description. One is a cyst and the other one is a lymph node.

May be benign: Most probably it may be benign like lipoma but better to get it checked up by a doctor

Boil.: If you thought it was a boil and it was red and warm and painful then it probably was a boil and is resolving. If not then it is something else such as a cyst. If it is very deep it could be a lipoma or lymph node, but these are easily distinguished from boils and cysts.