Thaw crab legs, rinse, and pat dry with a paper towel.
Place crab legs, cut side up, on a greased unheated rack of a broiler pan. Stir together melted butter, basil, lemon peel, and lemon juice.
Brush crab legs with butter mixture.
Broil 4 to 6 inches from the heat for 3 to 4 minutes or until heated through.
Serve with a side of melted butter for dipping.