The best smart locks can help anyone who constantly misplaces keys or who frequently wonders whether they locked the front door. Installing a smart lock doesn't mean throwing away your house keys—you probably still want to bring them with you. For more smart home recommendations, read our Best Video Doorbells, Best Outdoor Security Cameras, Best Indoor Security Cameras, Best Smart Speakers, and Best Smart Displays guides. I'm testing the Level Lock Pro ($349) and Nuki's Smart Lock ($159) next for this story. Best Smart Lock OverallYale's lock might look like it's a full lock replacement, but this is a retrofit design that only changes out the back of your thumb-turn dead bolt.