Nuki Smart Lock Ultra review: slimmer, smarter, and quieter

With the fifth generation of its smart door locks, Nuki is taking a different approach. The Smart Lock Ultra features a completely new design, a powerful new motor, and supports modern standards such as Matter and Thread. But is it worth the investment?

Anyone familiar with previous Nuki generations will immediately recognize the biggest change: the appearance. While previous models attached a rather utilitarian plastic box to the door, Nuki has now resolutely opted for elegance. The Nuki Smart Lock Ultra (€349 incl. VAT) looks like a sleek metal dial with an LED ring, finished in a stylish stainless steel look. It’s not just better looking, but also more compact.

However, there is a practical consequence to that slim design: the battery is no longer replaceable. Instead, you get a built-in battery that you charge via a magnetic USB-C cable. This cable clicks magnetically into place at the bottom of the lock and fully charges it in about two hours. After that, you’re good for several months, depending on usage.

Don’t have a power outlet nearby? Then you can also temporarily dismantle the lock and charge it elsewhere—though that is obviously less convenient. Or you can use a power bank that you likely have lying around somewhere.

Don’t be intimidated by the installation

The Smart Lock Ultra is the most compact model in the Nuki lineup, but that elegance comes at a price. Specifically, you have to replace your existing cylinder with the included Nuki cylinder. This task takes about twenty minutes and some handiness, but the Nuki app guides you through the process step-by-step with clear visuals and extra explanations.

Thanks to the included adapters, the cylinder fits most doors. A plus point is that you can still use keys (included in the box) on the outside—handy for housemates who prefer to stay analog.

Do keep in mind the maximum dimensions of the modular cylinder Nuki provides: 30 to 55 mm outside, 30 to 67.5 mm inside. In our situation, this was insufficient, and we had to buy a separate custom cylinder certified by Nuki. Prices are around €100 for a cylinder. This suddenly makes everything a lot more expensive, as you are already paying for the included cylinder with the Ultra.

You cannot order the Nuki Smart Lock Ultra without a cylinder. In that case, you end up with the Pro model (€269 incl. VAT), which is cheaper but requires a key and is less compact. Be sure to do your homework thoroughly beforehand. Especially in new construction projects where doors are often much thicker, the modular cylinder may not be adequate.

Noticeably quieter, lightning-fast opening

The Nuki Smart Lock Ultra is equipped with a new brushless motor. This is not only more wear-resistant but also noticeably quieter than its predecessors. In practice, this means the lock sounds less sharp—important in quiet homes or when coming home late at night.

When it comes to speed, we are in the top segment. In the fastest mode (appropriately named ‘Insane’), opening a double-locked door takes less than two seconds. That is faster than the competition from Aqara and Tedee. In softer modes (‘Standard’ and ‘Gentle’), opening takes a bit longer, but the smart lock is quieter—ideal for families with young children or light sleepers.

A small disadvantage: the motor’s torque is slightly lower than the previous generation (1.28 Nm vs. 1.50 Nm). This could play a role with older or stiffer locks. In our situation, the power was sufficient.

Smart, smarter, smartest

As you would expect from a premium smart lock, the features are spot on. Nuki’s famous Auto Unlock still works flawlessly: as soon as you step into the geofence around your home with your smartphone in your pocket and come within Bluetooth range, the door opens automatically. No more fumbling for keys—just walk right in. In our three-month test period, this worked perfectly every time.

Additionally, the lock supports Lock’n’Go: one press of the button when leaving the house, and the door locks itself after a few seconds.

The accompanying Nuki app is one of the most comprehensive of its kind. You can share access with others (via app, code, or fingerprint), set access times, manage recurring users, and very nicely: you don’t have to use an account or cloud connection if you don’t want to. Fully local use is perfectly possible.

Matter, Thread, and Wi-Fi

Nuki is playing it smart with smart home trends. The Nuki Smart Lock Ultra supports Matter and Thread—two crucial standards for future-proof home automation. Thread ensures a stable and energy-efficient connection via your smart speaker or hub, while Matter ensures the lock works seamlessly with Apple Home, Google Home, and Amazon Alexa.

Wi-Fi is also present, allowing you to operate the lock remotely, for example, to let in a delivery driver. Uniquely, Nuki allows users to disable Wi-Fi if desired and work purely on Thread—a great option for those who value privacy and energy consumption.

The Nuki Smart Lock Ultra is compatible with the full range of Nuki accessories. Think of a keypad, key fob, or even a fingerprint reader. The Keypad 2 (€159 incl. VAT) in particular is a valuable addition for families with children without smartphones, or as a backup solution.

Not everything is perfect

While both models are impressive, there are a few caveats. The magnetic charging connector works well, but sometimes feels a bit fragile and can—if used incorrectly—be pushed into the lock. This happened in one of our test situations.

The physical push button could also be better: the feedback isn’t consistent everywhere, so you’re sometimes not quite sure if you’ve pressed the button properly. Finally, the Nuki Smart Lock Ultra isn’t for everyone: the cylinder replacement is a hurdle for some users, as is the higher price.

Conclusion

The fifth generation of Nuki smart door locks takes a significant step forward. The Nuki Smart Lock Ultra (€349 incl. VAT) combines a beautiful, modern design with powerful performance and extensive features. The Ultra is the choice for those who want maximum aesthetics and aren’t afraid of a cylinder replacement. Those who already have a suitable lock are better off choosing the Pro variant—it’s cheaper and offers virtually the same functionality.