Simply, Taekwondo is open space combat and Hapkido is close combat. Taekwondo has less contact while training, can start as young as 4 years old and up to any age. Hapkido can start at 14 years old and up to any age. Taekwondo is considered modern martial arts. The beginning of Taekwondo training has easier techniques, such as letting the fist out or lifting the foot. Hapkido has many techniques that are joint attack. It is a more wild technique and is typically not suited for younger children.