A smart lock is arguably the most important part of a truly smart, connected home. Not only will it allow you to come and go as you please, it will also monitor who is entering and leaving your home while you're away. Some models simply let you use your phone to open and close doors. Some let you assign special privileges to friends, family members, or maintenance staff. Others can be activated using voice commands or triggers from other smart home devices and services

One of the first things you'll want to consider is how much it will cost to upgrade your traditional lock. After all, a smart lock costs a heck of a lot more than the standard-issue lock you can pick up at the local hardware store. You can find a few smart locks out there in the $100 range (not many of which made the cut for this list), but if you want a lock that you can control from anywhere, with features such as voice commands, push and email notifications, and tamper alarms, expect to pay somewhere in the $200 to $300 range.