After a year with the Nuki Smart Lock Ultra, the author's hesitation about IoT-controlled entry doors evaporated. The lock uses end-to-end encryption, requires no account to set up, and collects only the data needed to configure it. A contractor installed it over an existing Yale deadbolt in under 15 minutes, confirming the retrofit approach works without hassle.

The $359 price reflects what you get. Nuki encases the lock in stainless steel, keeps the footprint smaller than rivals, and offers Matter over Thread support for Google Home, HomeKit, Alexa, and SmartThings. The brushless motor has proven reliable but remains loud even in its quietest mode. Battery life started at two months between charges but has since shortened to roughly four weeks.

One design flaw involved a plastic cog meant to fail before damaging the motor. A guest opening the door while the motor was unlatching broke the cog, and with only two spares included, the author resorted to 3D-printing replacements. The Keypad 2 adds fingerprint unlock for hands-free entry. The Smart Lock Ultra is the best retrofit option available, and its security-first approach justifies the premium cost.