How We Test Door Locks

How We Test Door Locks

The deadbolts, electronic locks, and smart locks that enter CR’s labs get kicked, picked, and drilled into oblivion.

For the kick-in tests, CR’s test engineers built a custom jig that allows them to swing a 100-pound steel battering ram at a replaceable section of door with the deadbolt installed. They repeat the test eight times, at increasing heights, or until the lock fails. The models that fail—and at least half do—then go through another test round with a reinforced box strike plate installed on a new lock sample. Again and again, CR’s experts have found that this basic do-it-yourself upgrade improves security for any lock (more on that later).

For the drilling test, we evaluate how well each lock can withstand attack from a cordless drill. And for the picking test, we assess the internal mechanisms of each lock to see how easily they can be picked.

All models, including smart locks, receive a score in each of the four break-in tests, allowing you to easily compare each lock’s strengths and weaknesses in the face of a physical breach. The only exception is retrofit smart locks. These locks replace only the interior side of your existing deadbolt, essentially adding smarts to the lock you already use. As a result, a retrofit smart lock’s resistance to kicking, picking, and drilling is entirely dependent on the deadbolt it’s paired with.

Both types of smart locks also get additional testing. We investigate features such as smartphone alerts, remote locking and unlocking, geofencing (the ability to automatically lock or unlock the door based on your phone’s location), voice control (via Amazon Alexa, Google Assistant, and Apple’s Siri), shareable electronic keys, access logs of who comes and goes, and even tamper alarms. Our testers factor these features into our ratings for ease of remote access, convenience, and security add-ons. We also run through the wireless setup process to see how difficult it is to connect the locks to a smartphone and other smart home devices (such as smart speakers), putting ourselves in your shoes. For the details on how well each door lock performs in these tests, see the results in our door lock ratings.