Smart Locks and Video Doorbells: What to Check Before You Buy

Two of the most popular smart home devices are also two of the easiest to get wrong on the first try.

Smart locks and video doorbells are consistently among the first smart home devices people buy — they solve real, everyday problems: knowing who's at the door, letting in a dog walker without a physical key, checking that the door actually got locked after you left. They're also two of the devices most likely to cause a genuinely bad day if the compatibility check gets skipped.

Before buying a smart lock

• Deadbolt type and dimensions. Smart locks are designed around specific deadbolt formats. Door thickness, backset (the distance from the door's edge to the center of the lock), and existing hardware all affect whether a given smart lock will actually fit your door without modification.
• Power backup. Nearly all smart locks run on batteries, and battery failure at the worst moment is a real (if uncommon) scenario. Check whether the lock has a physical key backup, an external battery jump-start option (often a 9-volt battery contact on the outside), or both — a smart lock with no manual override is a risk not worth taking.
• Connectivity method. Some smart locks connect directly to Wi-Fi; others require a separate hub to enable remote access and notifications. A hub-dependent lock adds another point of failure and another device to keep powered and updated.
• Ecosystem compatibility. Confirm the lock works with whichever smart home platform (Apple, Google, Amazon) your household already uses, the same way you would for any other smart device.

Before buying a video doorbell

• Wired vs. battery — covered in more depth in our wired vs. wireless doorbell guide, but worth deciding before you buy, not after installation reveals the tradeoff.
• Cloud storage and subscription costs. Many video doorbells require a paid subscription for full features like video recording history and person detection — check what's actually included for free versus what requires an ongoing monthly cost before comparing prices between brands.
• Field of view and mounting height. A doorbell mounted too high can miss packages left on the ground; one with a narrow field of view can miss someone approaching from the side. Check the specific angle and consider your porch's layout before mounting.
• Existing doorbell wiring compatibility, if you're considering a wired model — not every home's existing low-voltage wiring and transformer supply enough power for a modern video doorbell without an upgrade.

The compatibility check that saves the most headaches

For both devices, the single most valuable thing you can do before buying is measure and photograph your existing door hardware or doorbell wiring and check it against the manufacturer's compatibility specs — not just the general product description, which is often written to sound universally compatible even when specific dimensions or wiring types are excluded in the fine print.

A word on smart locks specifically

Unlike most smart home devices, a smart lock failure has an immediate, physical consequence: you can end up locked out of your own home. It's worth treating this purchase with slightly more caution than a smart bulb or plug — confirm the physical fit, confirm the backup power option, and consider a professional install if you're not fully confident measuring and swapping deadbolt hardware yourself.