Hanuman had too much powers in his body and Lord Rama also had many powers and he killed Ravana. But I want to know that who was more powerful? Rama or Hanuman?
Hinduism believes each god (not only in hindus but also in christion , muslims) is avatara (part) of bhagavan shrikrishna.
Comparison between two gods on the path of spirituality is called "Namaparadh".
Shriram was avatara of bhagvan vishnu , so undoubtedly Shriram was great , but Lord Hanuman was his bhakta. And in this age we need to learn the Nishkam bhakti like Lord Hanuman that no one does on Supreme god. So Lord Hanuman was also great.
You can not compare the greatness of one god with other. God is one as told in Gita.
This sloka about Hanuman, captures very well, Hanuman's abilities :
Manojavam Maruthu thulya vegam
Jitendriyam Buddhi mathaam varishtam
Vadhaatmajam Vanara yoodha mukhyam
Sri Rama dhootham Sharanam Prapatye*
To The one who is as fast as wind and mind, The one who is a master of senses, The one is the best among the intelligent, The son of Vayu, the Lord of Wind, The one who is a leader of the Vanara,s The messenger of Lord Rama, To him I offer my obeisances.
The sloka captures many attributes of Hanuman, ironically, much revered in the modern world as well) : 1. Speed 2. Self-Mastery 3. Intelligence 4. Lineage 5. Leadership
However, the last line captures Rama's glory.
What makes Hanuman a great devotee is that, having endowed with all these supreme attributes, he offered these in the service of Lord Rama and became his messenger. Ravana had even more knowledge than Rama, but what was the use, his lack of mastery over himself brought his doom.
Rama was more powerful, because he could command the love of Hanuman, who had the power of physique and faculty and could re-direct them towards the establishment of Dharma. The ultimate power is the power of Inspiring people with love.