I was always under the impression that handsome was the male version of beautiful. I now hear people going "nah.. he's not handsome, he does look beautiful though".
And please, this is not describing personality - looks only.
Most Helpful Girl
Handsome is maybe more traditionally masculine and also sounds sort of old fashioned and formal. I'm more likely to call a guy I find attractive beautiful because saying beautiful has kind of less hegemonically masculine connotations and I go more for guys who have both masculine and feminine qualities, eg. looks-wise they'll maybe have more delicate features for example, and have a slighter frame. Also as Mocha_Queen said handsome very specifically references physical appearance whereas beautiful I feel like is a broader term and can be in reference to their personality as well, so they may be beautiful in that they're kind, compassionate, sensitive etc.0