It's impossible to definitively say who the "prettiest" K-pop idol in the world is, as beauty is subjective and varies greatly from person to person.
Beauty standards are influenced by cultural norms, personal preferences, and individual perceptions. What one person finds attractive, another might not.
There are countless talented and beautiful K-pop idols, each with their own unique features and charms. It's more about appreciating the diverse beauty and artistry within the K-pop industry rather than trying to rank idols based on a subjective concept like "prettiness."
Instead of focusing on a single "prettiest" idol, it's more meaningful to celebrate the individuality and beauty of all K-pop idols and the impact they have on the world through their music and performances.