The Nuki Smart Lock installs over your existing deadbolt in place of your interior thumb turn, and you can control it from your phone, any major voice assistant, or a keypad (sold separately). It's easy to install and works quickly and quietly. Its $159 price is reasonable, but Wi-Fi control costs extra. I also encountered some performance issues in testing, including spotty Bluetooth connectivity and unreliable auto unlock functionality. Ultimately, the fee-free $229.99 August remains our Editors’ Choice for retrofit smart locks, and you can often find it on sale for much less than its list price.

Design and Features: Retrofit Smarts

While Nuki has been making smart locks for years, this is its first model to arrive in the US after five generations of launches in Europe. Nuki's claim to fame is speed. Other smart locks take a second or two to open, but Nuki's brushless motor snaps open the deadbolt in less than a second after receiving the command.

The Nuki Smart Lock is a retrofit model, which works better for renters than replacing the entire deadbolt. The physical bolt from your existing lock stays put, as does the exterior key hole. You simply install the Nuki in place of your interior thumb turn, so you can keep using your existing keys (as can your landlord).

The lock's squat, cylindrical body measures 2.2 inches in diameter, and at a glance, it reminds me of the August lock. The majority of the exterior is stainless steel, with a black plastic ring at the base. The top of the cylinder has a button for setup, locking, and unlocking. The button is surrounded by an LED that blinks to warn you if the door is unlocked.

(Credit: Andrew Gebhart)

The Nuki Smart Lock does not include a sensor that lets you monitor whether the door, not just the lock, is open or closed. This useful accessory is included with the August lock and the Yale Approach ($129.99). However, you can buy a door sensor separately for $59.

Moreover, unlike August and Yale, Nuki hides some ordinary app features behind a $5.90 monthly paywall. The free Nuki app (available for Android and iOS) lets you control the lock within Bluetooth range, set up the auto unlock feature, and configure some settings.

You’ll need a Nuki Premium membership to control the lock via Wi-Fi, so you’re out of luck if you only have the basic version and need to open your door for a friend when you’re out and about. Nuki Premium also includes real-time activity alerts and a few other niceties, like product replacement in case of a defect and built-in compatibility with hosting platforms like Airbnb. Through the end of September 2025, US buyers can get a free membership for the life of their device as part of the brand's launch promotion.

(Credit: Andrew Gebhart)

The Nuki lock is compatible with all major smart home device platforms, including Amazon, Google, HomeKit, and SmartThings. If you have an established smart home ecosystem, you may be able to get around the app’s pesky premium for remote control over Wi-Fi. Since the Nuki Smart Lock is compatible with Matter, syncing it to a Thread Border Router will give you the ability to remotely control it outside Bluetooth range using your existing smart home assistant. Current HomePods and Apple TVs work as border routers for HomeKit. If you use Alexa, your options include recent Echo Show displays and Eero routers. Google’s recent smart displays and routers work for this as well. For comparison, the August lock does not require a membership for Wi-Fi control, and works with Amazon, Google, and HomeKit, but doesn’t support Thread.

Other than app and voice controls, you can lock and unlock the Nuki Smart Lock with an optional keypad. The Keypad 2 (available on its own for $159, or in a bundle with the Nuki Smart Lock for $318) lets you open the door with a numeric code, and has a fingerprint sensor on the bottom for an additional means of entry. Nuki is also planning to launch a code-only keypad for $89. For this review, Nuki sent me the Smart Lock and the Keypad 2.

Setup: Simple and Easy

The Nuki Smart Lock comes with safety and warranty information, QR codes for the app and Matter setup, a measuring card for installation, and mounting hardware like a base plate, screws, and three different fitting adapters for your door. It also comes with a long USB-C charging cord that magnetically attaches to the outside of the lock. If you have an outlet within reach, you can charge the lock without uninstalling it. It doesn't come with a wall adapter for the charging cord, which isn't unusual for smart home devices.

To get started, I first charged the lock since I don’t have an outlet near my front door, and downloaded the Nuki app in the meantime. You can avoid using this app entirely if you have a Matter-compatible Thread Border Router, as you can then do setup via your platform of choice. The Nuki app offers installation instructions if you need the reference, and doesn’t even require you to create an account for the basic version.

The retrofit gadget is compatible with single-cylinder deadbolts from various lock manufacturers, and it fits perfectly on my Kwikset bolt. In addition to the hardware in the box, you will need a Philips-head screwdriver for installation.

When you open the app, it prompts you to allow notifications and location access. You then need to hold the button on the lock for five seconds and set a security code that the app will ask you for when trying to make future changes. The app then asks if you need help with installation. The instructions are clear and helpful, with illustrations, though the process is mostly intuitive if you’ve installed smart locks before and want to skip over the help.

(Credit: Andrew Gebhart)

After securing the exterior of my lock with the included tape, I removed my existing interior thumb turn with a screwdriver. I used the included measuring card to make sure my bolt’s tailpiece overhang would fit with the lock base. Nuki includes a base extender in case your tailpiece is a little long. I then attached the mounting plate with the existing screws from my thumb turn, chose a fitting adapter to match the shape of my tailpiece, and slid it in place.

Nuki tells you to make sure that the notch on the mounting plate is facing upward when in place. The picture shows the notch colored in yellow, and it took me a while to realize that there was no yellow mark on the plate itself, just a notch, with the yellow in the app serving as an indicator. I ran into the same confusion with the main body of the lock itself, which also has a notch.

(Credit: Andrew Gebhart)

Once you find the notches on both the lock and the mounting plate, installing it is as easy as sliding it into place with the notches aligned, and then turning the base to the right to secure it. The lock then automatically calibrates and locks and unlocks a couple of times. You can optionally set up your geofence location in the app for the automatic unlocking feature.

If you set up the lock in the Nuki app and want to control it with a third-party voice assistant, you will need to create a Nuki account. From the Nuki app, go to Settings > Features and Configuration > Nuki Web > Create an Account. Then you can add the Nuki skill to your digital assistant's app and sync accounts. Note that by default, Nuki will only allow your door to be locked with voice commands. You need to manually enable unlocking by voice in the app settings.

I easily synced the Keypad 2 by hitting the menu button in the upper-right corner of the app’s home screen, then Manage Devices > Accessories > Keypad. The app walks you through the simple setup and pairs the lock to the keypad via Bluetooth. You set up the code to unlock the door, and then have the option to add a fingerprint and toggle on the ability to lock the door by tapping the back button on the keypad. I did both, and then attached the Keypad 2 to my exterior door frame.

The Keypad 2 doesn’t come with any mounting hardware, just a covered strip of 3M adhesive on the back of the device itself. When I first stuck it in place, the tape didn’t seem all that secure, and I pulled it free easily. I then stuck it back in place and left it for a while to set. To my surprise, the Keypad 2 stayed put, though some means of mounting it in a more permanent way or replacing the batteries without pulling the whole contraption down would have been appreciated.

Controlling the Lock: Intuitive Options

Once the lock is in place and set up, you can lock and unlock the bolt by pressing the physical button on top of the cylinder. You can also turn the cylinder itself. If the door is locked, you can press the button twice for a unique Lock ‘n’ Go feature that unlocks the door long enough for you to exit, then automatically locks itself again roughly half a minute later. The LED surrounding the button will blink if the door is unlocked as a visual reminder that your entryway isn’t secure.

(Credit: Nuki/PCMag)

The simple Nuki app replicates these controls. The main page shows the lock’s status. Tap anywhere in this status area to bring up a drawer with buttons to Lock, Unlock, or Lock ‘n’ Go. A settings button at the top of this drawer lets you configure Auto Lock, disable the blinking LED when the door is left unlocked, and set up smart home integrations like Matter or Alexa. Tap the menu button in the upper left to add new devices to your Nuki setup, or add approved users who can control your lock.

(Credit: Andrew Gebhart)

I’m paranoid about leaving my door unlocked, so I didn’t often use the Lock ‘n’ Go function. Pressing the back button on the Keypad 2 to lock the door was quick and reliable. Every now and then, it would take a couple of seconds to wake up and find a connection. Using my fingerprint to unlock the door performed similarly. It always worked, but sometimes the lock or the keypad needed a second or two to wake up.

Performance: Good, With Caveats

Before I signed up for the premium subscription, controlling the lock without the Keypad 2 was hit or miss. The button on the lock itself worked well, though it occasionally showed a second of lag, like the keypad. Controlling the lock with my phone was less reliable. It stayed connected well enough at first, but then, after a day or so, I struggled to get my phone to work with the lock over Bluetooth, even when I was standing right next to it.

Oddly, the auto unlock feature continued to work during this stretch, so it recognized my phone was in Bluetooth range, but I still couldn’t open the app and manually control it without at least a few minutes of fiddling and resetting the connection.

After I set up my premium subscription, the lock worked much more consistently. Like the Keypad 2, it sometimes took a moment to wake up, but I was always able to reliably control it with the app after a second or two.

I continued to use the auto unlock feature throughout my testing, and its responsiveness became slightly more sporadic as time went on. Sometimes, it would recognize my approach and engage slowly. Other times, it didn’t respond at all, and then it would respond perfectly on my next outing, with no discernible difference between the events.

I also synced the lock to my Alexa account, and controlling it with voice commands proved to be as consistent and reliable as using the Keypad 2.

After roughly a month and a half of testing and regular use, the lock's battery is at 58%, so I expect it to last over three months on a charge. It does a good job of conserving power during use, which might explain why it sometimes takes a moment to wake up even when it receives a command. That three-month-plus timeline is less than the company’s estimated 12 months on Wi-Fi, but on this front, the Nuki Lock is superior to August, which gets three months of battery life from disposable coin cell batteries. Nuki’s batteries likely last longer and are rechargeable.