The latest generation of “smart” locks for your home’s ­exterior doors offers features that make the locks even more convenient and useful. These include “geofencing” technology that senses when your smartphone is a certain distance from your door and automatically unlocks it…and the ability to use voice commands to lock or unlock your door.

Our picks for the best smart locks work with Android and iOS devices and aren’t difficult for home owners to install themselves. They are available at manufacturers’ websites, home stores, major electronics retailers and online.

Yale Real Living
Assure Lock Key Free
Touchscreen Deadbolt

Best smart lock if you’re OK replacing your existing deadbolt: Yale Real Living Assure Lock Key Free Touchscreen Deadbolt with network module. The stand-out feature of this lock, which replaces the traditional keyhole on the exterior of your door, is an electronic brain that can connect to most major smart-home systems including Apple HomeKit (which uses Siri for voice commands), Amazon Alexa and Google Home. With this feature, as you approach your home, you can say to your smartphone, for instance, “Siri, open the front door.” You can designate a specific word or phrase, such as “Alexa, lockdown,” to trigger a set of actions for multiple smart-home connections such as, at bedtime, shutting off inside lights…turning on certain outside lights…and locking the front door. The lock’s app allows you to create daily schedules to make sure your lock is open or closed at the same time each day. As a backup, the lock has a touchscreen keypad that lights up when you put your hand over it and a tamper alert that sounds an alarm if an attempt is made to forcibly remove the keypad. Yale has a reputation for top-quality keypad locks that offer more safety than keyhole locks, which can be picked fairly easily. Cost: $220.

August Smart Lock
Pro + Connect

Best if you don’t want to replace your existing deadbolt: August Smart Lock Pro + Connect is a retrofit lock that fits over the interior thumb latch of your door’s existing deadbolt, leaving the lock on the outside of your door unchanged so that you can continue to use your existing keys as backup. It’s one of the more expensive smart locks, but it is packed with appealing features. If you have friends and family or repair and delivery people who come by often, or you rent out your home to travelers, you can transmit to these people individualized “digital keys” that they use on their smartphones, and you can restrict when and for how long the keys work. You can turn on the lock’s geofencing feature to have it automatically unlock the door when you approach the house and lock it when you leave the house. The lock’s DoorSense feature provides a basic security alert, texting you when you have inadvertently left the door open—a common mistake. August has partnered with several popular home-security providers such as and SimpliSafe so that the lock can operate in coordination with security-system components. That means, for example, that when you lock and unlock your door, you can conveniently activate or deactivate your alarm system at the same time. Cost: $279.