I was initially hesitant to get a smart lock; I didn’t like the idea of using an internet-connected product to control the main door. I have dozens of smart home products in the house, and while I don’t mind using them, I’m still wary about security vulnerabilities, which is why I put all IoT devices in their own VLAN.
These fears proved unfounded once the Nuki Smart Lock Ultra showed up. I wasn’t familiar with Nuki, but it’s the rare smart home brand that cares about security. The Smart Lock Ultra comes with end-to-end encryption, I didn’t have to set up an account to use it, and Nuki didn’t ask for any data outside of what’s needed to set up the device.
Honestly, it’s such a refreshing change of pace to most other smart home products I use that I recommend Nuki just for its security practices. Of course, there’s also the fact that the Smart Lock Ultra is a great piece of kit; I really like the design of the lock, and after a full year of use, it has proven to be unerringly reliable — something I can’t say about any other product I tested in this category.
All of these positives come at a cost, however. The Smart Lock Ultra is available for $359 in the U.S. and costs €349 in Europe, and you’ll ideally need to get the Keypad 2 as well, with the bundle going up to $409/€429. Now, what are you getting for what price? The Smart Lock Ultra is unquestionably the best retrofit smart lock around, and the design along with sensible security measures give it a sizeable advantage.
The Smart Lock Ultra is a retrofit solution, so you can install it over an existing deadbolt. The lock comes with its own universal cylinder that’s designed to fit most door profiles, and it’s pretty straightforward to install. I set it up while getting the house interiors done, and the contractor was able to install it in under 15 minutes. I had an existing Yale lock on the door, and it wasn’t any problem to slot in the Smart Lock Ultra over it. Nuki provides all the requisite parts, and the lock comes with three sets of keys that can be used to manually unlock the cylinder (you can order more as needed on Nuki’s site).
The Smart Lock Ultra is encased in stainless steel, and it’s much smaller than most of its rivals. The design itself is quite elegant, and the base of the unit has an interchangeable plastic ring that’s available in white or black. The unit has an LED ring that flashes white when the door is unlocked, and red when the built-in battery needs to be charged. It’s a well-designed product, and I didn’t run into issues with installation or usage over the last year.
Nuki went with a brushless motor, and it has proven to be reliable. It does get quite loud when unlocking, and while there are three modes, even the quietest Gentle mode can get pretty loud. Controlling the lock is best done with the Nuki app; it has a minimalist interface, and plenty of features to get the most out of the lock. You can easily configure auto unlock, night mode — which automatically locks the door — and set up the built-in Wi-Fi. Once you connect the product to your home network, you can control it remotely from anywhere in the world, and even after a year of use, it’s just cool to be able to do that.
You can control the Smart Lock Ultra with just about any smart home platform. It integrates with Google Home, HomeKit, Alexa, and Samsung’s SmartThings platforms, and comes with Matter over Thread. I also got the Keypad 2, and I use it to unlock the door with a fingerprint. You can set up a numeric lock as well, and it’s a nifty solution if you want to give someone access to your home.
The one problem came two weeks ago when a plastic cog that sits in between the motor and the thumb turn broke. This cog is designed to fail so as to not damage the motor, and in that regard, it worked as intended. Basically, a guest tried to open the door while the motor was still unlatching, and the cog broke as a result. Nuki bundles two of these cogs with the Smart Lock Ultra, but it should ideally provide more; we broke one initially while calibrating the product, so there weren’t any left to use with the lock. Thankfully, there’s a 3D-printed solution that came to the rescue. I got the part 3D-printed, and it slotted into the lock without any issues (I got 20 of these made just in case).
Battery life has been decent overall, with one caveat. I initially had to charge the Smart Lock Ultra once every two months, but nowadays, I’m having to plug in the charger every four weeks on average. Nuki has a charger with a USB-C port and a pogo pin on the other side, and it’s convenient to just use a power bank to charge the product while it’s connected to the door (it just needs 10W of power). I recently got a new router system, and I switched the built-in Wi-Fi to Compatibility mode, which according to Nuki uses more battery. I reverted the setting to the Automatic mode, and I’ll update this post if I notice a difference in the battery life next month.
On the whole, the Smart Lock Ultra is the best retrofit solution around. It’s effortless to set up and use, looks great, connects to every smart home platform, and has class-leading security features. Yes, it costs more than its rivals, but you’re also getting a much better overall product, and a level of trust that you don’t normally see in this category. That alone makes it easy to recommend the Smart Lock Ultra if you’re looking to get an internet-connected product to lock your door.












