How to keep your old keys with a new smart lock

Smart locks are a convenient way to manage access to your home, but many models require replacing the entire lock mechanism, including your deadbolt. 

What can you do if you don't want to ditch your existing lock and keys? Check out these smart lock options. 

The Kwikset Kevo Convert is a retrofit smart lock designed to install on the back of your existing lock. It comes with detailed instructions and extra parts and adapters to ensure a good fit. 

Inside the Kevo app, you'll find controls for your new smart lock. Check your lock's status or lock and unlock it remotely if you're within Bluetooth range or have a Kwikset Kevo Plus gateway device installed. 

With the Kevo Plus installed, this lock integrates with Amazon Alexa. It also works with Ring, Skybell and Nest products, select Honeywell Thermostats, Android Wear and IFTTT.

The Sesame Smart Lock from Candy House is a retrofit smart lock in the style of its biggest competitor, August. 

The lock's signature feature is a "knock to unlock" capability that unlocks your door when you knock on the screen of your connected mobile phone. 

Installing the Sesame Smart Lock is as simple as clipping it onto the thumb latch of your existing lock. Adhesive strips along the bottom and top hold the lock in place. 

The Sesame is powered by two CR123A 3V lithium batteries.  

In the Sesame app, you can view the live status of your lock and control it remotely if you have a Sesame Wi-Fi Access Point installed in your home. 

The Sesame only works with smart home platforms via IFTTT right now. Integration with Google Assistant and Amazon Alexa are still to come.

The August Smart Lock Pro got our Editors' Choice Award for a smart lock. It's a reliable Z-Wave lock that integrates with Google Assistant, Amazon Alexa and Apple HomeKit and it has a great app. 

The lock simply clips onto the back of your existing deadbolt's thumb latch and is powered by AA batteries.

The August app supports all of August's smart locks and is a simple way to manage access remotely, if you have an August Connect Wi-Fi module installed. 

The Pro and third-generation August models include DoorSense, which lets you know in the app if the door is locked or unlocked and if it's open or closed.

You can still purchase the more basic August Smart Lock model, now in its third generation. 

This newest model adds DoorSense and boasts a physical redesign, but it doesn't work with Apple HomeKit. 

By far the best-looking smart lock we tested, the Friday Lock is a modern approach to traditional lock hardware, and its metal shell comes in multiple finishes to match your home's decor. 

This Bluetooth smart lock doesn't come with as many smarts as other retrofit locks, but if you're looking for a lock that works with Apple HomeKit and via Bluetooth, this is one great-looking option.

Like the Friday Lock itself, the Friday app looks great, too. You can view and manage user access and control the lock remotely when you have an iPad or Apple TV set up as your HomeKit hub.