How do you say you're cute in spanish?

It depends on what you mean by "cute". If it is "pretty" for a girl, it would be "eres guapa" or "eres bonita" or "eres atractiva". For a boy, "eres guapo" or "eres atractivo". If you mean "precious" or "darling", "eres cuco". Example: "That's a cute sweater" would be "es un suéter cuco".