When do you actually let them browse the internet unsupervised?

My 10yo is becoming more independent and wants to look up random stuff on Google. Right now I'm hovering and checking what he's searching, but that feels like it's going to get old fast. He's not seeking out bad stuff - it's mostly Pokemon facts and dinosaurs and cooking videos. At what point do you let them have some privacy/independence with browsing? What safeguards do you put in place?