Start with fit: measure your door's backset and thickness and choose a lock that fits your existing deadbolt holes, or a retrofit that keeps your current exterior hardware. Then compare BHMA security grades, entry methods (keypad, fingerprint, app, key), connectivity (Matter, Thread, Wi-Fi, Z-Wave), battery life and how you get in if the batteries die.
A smart lock replaces keys with codes, fingerprints or your phone. It still has to be a good lock first.
Fit first
| Measurement | Typical US value |
|---|---|
| Bore hole | 2-1/8 inch |
| Backset | 2-3/8 or 2-3/4 inch |
| Door thickness | About 1-3/8 to 2 inches |
Retrofit smart locks replace only the interior side and keep your exterior deadbolt and keys.
Security
Look for a BHMA grade on the deadbolt (Grade 1 or 2 for exterior doors), a reinforced strike plate with long screws and, where available, auto-lock.
Entry methods
| Method | Notes |
|---|---|
| Keypad | Guest codes, no phone needed |
| Fingerprint | Fast for family |
| App and phone | Remote access, logs |
| Physical key | Backup; some models have none |
Connectivity
| Option | Notes |
|---|---|
| Matter over Thread | Works across ecosystems, local, needs a border router |
| Wi-Fi | No hub, more battery use |
| Z-Wave or Zigbee | Needs a hub |
| Bluetooth only | Works nearby; remote access needs a bridge |
See smart-home standards for the details.
Power and lockouts
Check battery type and life, low-battery alerts and the backup entry method. Know how to get in before you need to.
Browse security and access.
Common questions
Will a smart lock fit my door?
Most fit standard US deadbolt prep: a 2-1/8 inch bore with a 2-3/8 or 2-3/4 inch backset on doors about 1-3/8 to 2 inches thick. Check the lock's specs.
What is a BHMA grade?
A rating from the Builders Hardware Manufacturers Association based on durability and strength tests. Grade 1 is the highest.
What happens if the smart lock batteries die?
Most warn you for weeks first. Backups include a physical key, external battery terminals or USB power.
Do smart locks work with Matter?
Many newer models do, often over Thread. Check for Matter certification and your controller's support.