Popular European smart lock maker Nuki has announced the fifth generation of its smart lock. The Smart Lock Ultra is a third the size of the original Nuki, features a new brushless motor for faster operation, and promises at least six months of battery life. Plus, for the first time, the new lock has been designed to work with US deadbolts.

The Nuki Smart Lock Ultra (€349) will be available in Europe in December and is the company’s first full-replacement door lock. Previous Nuki models could be retrofitted over an existing lock, so you could keep using your existing keys. This one requires swapping out the entire cylinder and comes with three new keys. However, the US model, coming next year, will work as a retrofit lock and only require replacing the thumb turn on your door — similar to how the August smart lock works.

Martina Stix, Nuki’s communications manager, tells The Verge that the US version looks identical but comes with a different mounting plate and no replacement cylinder — so you can use your existing keys. She says it should be available in Q2 of 2025, with pricing still to be determined.

The big change here is that the Nuki Ultra packs all of the functions of the previous model into a much smaller design thanks to a new built-in battery that does away with the bulky battery compartment. The company says it’s also over three times faster — capable of locking or unlocking in under 1.5 seconds.

That’s very fast; the fastest locks I’ve tested take two to three seconds to fully unlock, and most are closer to five, especially retrofit locks. Stix says the speed comes from an all-new motor: “The new smart lock is powered by brushless engine technology, commonly used in electric cars, used for the first time in a Nuki smart lock.”

The lock can be controlled in several ways: with a key, with geo-fenced-based auto-unlock, with the Nuki app on a phone or smartwatch, or with any compatible smart home platform. It also works with all existing Nuki accessories, including a key fob and a separate Bluetooth keypad mounted outside the door, with the option of a fingerprint reader.

As with the Nuki Smart Lock (4th-gen) launched last year, the Ultra offers a choice of connectivity options: Wi-Fi, Matter-over-Thread, or Bluetooth. It supports Apple Home, Amazon Alexa, Google Home, Samsung SmartThings, and other Matter-compatible platforms.

The company’s existing keypad accessory does not support Apple’s Home Key function, which allows you to tap your iPhone or Apple Watch to an NFC-enabled lock or keypad to unlock it. Stix says Nuki plans to support Aliro when it launches next year, a new standard for smart locks that is reported to include a similar tap-to-unlock capability to Home Key, although the specification has not yet been released.

Unlike some previous generations of the lock, Wi-Fi connectivity is built into the Nuki Ultra, so there is no need for a separate bridge. The new battery technology promises up to six months of battery life (possibly more, depending on your connectivity choice; Thread or Bluetooth will last longer than Wi-Fi). But it does have to be charged on the door, which seems a bit awkward. The company supplies a two-meter magnetic power cable to reach a nearby outlet and says it can fully charge in under two hours.

The Smart Lock Ultra is available for preorder now at Nuki.io in Europe for €349 and will ship in December. The US version is expected to launch next year.