Are smart locks secure? What to look for before you buy

Smart locks are convenient: no keys to lose, codes for guests, and a log of who came and went. But convenience and security aren't the same thing. A good smart lock, installed well, is as strong as a quality deadbolt. A poor one is not.

Start with the lock, not the app

A smart lock is still a lock. Before looking at features, check the mechanical side:

• Hardware grade. Look for an ANSI/BHMA grade on the packaging or spec sheet. Grade 1 or 2 is a good sign. If no grade is listed, be cautious.
• A real deadbolt. The bolt should be a full deadbolt, not a spring latch.
• The door and strike. Even the best lock depends on the strike plate and the frame. Long screws into the framing matter more than any feature in the app.

Think about backup access

What happens when the battery dies or the Wi-Fi drops? Most smart locks warn you well in advance and offer a backup, such as a physical key, a keypad or external battery contacts. If there's a key cylinder, it's worth knowing it can be picked like any other lock. Some models accept higher-security cylinders.

Codes are only as good as how you manage them

• Give each person their own code so you can remove one without changing everyone's.
• Use temporary or scheduled codes for cleaners, trades and guests.
• Avoid obvious codes like 1234, birthdays or the street number.
• Wipe fingerprints off keypads occasionally. Worn buttons can give a code away.

Keep the software side tidy

Use a strong, unique password on the lock's account and turn on two-factor authentication if it's offered. Keep the app and the lock's firmware updated. Buy from established manufacturers that release security updates.

Installation matters

Many smart locks fail because they're installed on a door that doesn't close cleanly. If the bolt has to fight the strike, the lock motor strains, batteries drain and the lock may report "locked" when it isn't. A properly aligned door fixes most of these problems.

The bottom line

Choose a graded lock from a reputable maker, install it on a door that closes well, and manage codes carefully. Do that and a smart lock is a genuine upgrade, not a weak point.