For the past year or so, I've been looking at smart locks and wanting one yet not able to fully commit to anything. Living in Lebanon means our doors don't have the American-style deadbolts, but what is known as the Euro Style/Profile Double Cylinder - a lock that is quite prominent across France, Germany, the UK, and other countries. So August, Yale, Schlage, Kwikset, and plenty of brands geared toward the US market were mostly out of the question unless I wanted to take a risk and get something that doesn't fit at all with my apartment's door.

That was until I stumbled on Nuki's smart lock, which is compatible with the Euro Profile Cylinder (and a couple of other lock models). At first, I was quite skeptic: I couldn't trust the security of my apartment's door to a brand I'd never heard about. But feedback on Amazon was positive, the few videos I saw showed it working very well, and even the Play Store app's rating and reviews were enthusiastic (these usually are a more accurate metric than Amazon reviews of people's experience with a product). I'll spare you the details of my week-long research into Nuki's solution and jump straight to the end: I was more than intrigued and reached out to the company for a review unit. I figured, worst case scenario, I'd easily remove it and go back to my regular lock.

Then I got the lock more than a month ago and from A to Z, I was impressed with everything the company has done. Not only has the Nuki not failed me a single time, it has also won over my husband. It was tough to convince him to surrender our lock to something smart, but he quickly came around to appreciating its benefits over time.

The Good

Build quality The Nuki lock looks good and is very sturdy and well built. No creaks or flimsiness to be seen.
Easy installation It installs over your existing lock and key, which took all of 2 minutes to do. It took just as much to pair it with my phone.
Inconspicuous The Nuki installs on the inside of your door, so would-be thieves can't tell that it's there.
Use your key You can still use your key to open the door from the outside (if your double cylinder lock has an emergency function).
All of the options The Nuki app has every option I thought I needed, every option I realized I needed after seeing it, and even more options I don't know if I'll ever need.
Security End-to-end encryption, Bluetooth only (without the bridge), pairing disabled, no username and password (without the bridge)... A lot of thought went into making the Nuki as secure as possible.
Convenience A smart lock is super convenient if you forget/lose your keys, have a temporary guest, need to let someone you trust in while you're away, and monitor the state of your door.
Consistency and responsiveness Of all the apps and all the smart home gadgets I've tried, Nuki has been the most solid. Never disconnected, reliable Bluetooth connectivity, the bridge is quick to reconnect when my network goes down, and always quick to execute a command.
Integrations Nuki currently works on Android, Android Wear, iOS, Apple Watch, and you can enable a Web component. And beyond that, it integrates with Google Assistant, Alexa, and IFTTT.

The Not So Good

Price Nuki isn't cheap, at all. €229 for the lock alone is a steep price to pay for the convenience of having a smart door lock.
Loud The sound of the mechanism when you lock and unlock the door isn't subtle. You can hear it from several meters away.
Bridge's build quality It's plastic and flimsy. Compared to the lock, the bridge feels like an inferior product. Thankfully you don't have to look at it at all once it's plugged and set.
Bridge's range You need to have an outlet less than 3m away from your door for the bridge to connect reliably. Any more and you won't be able to even pair it with the lock.
Some concerns There is always a question of security when installing a smart door lock. If modern tech has taught us anything, it's that vulnerabilities can't be avoided.
Few missing options No setting to auto-lock the door after it's been unlocked for x minutes, no notification when someone else unlocks the door, and no reminder to set up a PIN for security when you invite new users.
Integrations again Nuki isn't officially supported on SmartThings or Wink. That would have made some routines and other actions easier to implement.

Installation and setup

Part of the reason I loved the idea of Nuki was the fact that it doesn't replace your entire lock, but installs over it and acts by turning the key, like August does for deadbolts in the US. Before you buy it, you need to make sure that it fits your current lock and key, which requires validating a couple of checkpoints and measuring your key and how much it protrudes. Once you're sure things will work and you purchase the Nuki, the installation is a super fast process.

The lock comes with two plates: one if the overhang is large and you can "screw" the plate on (with an Allen key), the other if the overhang is small so you can just stick the plate on. The video below demonstrates this much better than I can explain with words. In my case, I had to use plate B. The whole process of finding the right plate, sticking it to the lock, inserting the key, and installing the battery-powered Nuki on top took about 2 minutes, start to finish.

Once that was done, the Nuki was solidly attached to the door and hasn't budged in the month or so that we've been using it to lock, unlock, and open the door's latch. The size is a little large but the round cylinder controls the key and the black box beneath it houses the batteries. A second generation of the product should definitely be smaller, but as a start this isn't very annoying or intrusive. A second generation should also offer different finishes: the silver and black don't mesh well with our brown wooden door and brass handle. But again, as a start, it doesn't look half bad overall.

The build quality of the Nuki is solid. Though most of it is plastic, it's well done plastic with little give and no creaks or signs of weakness. Even when it's exerting the power to turn the key in the lock, it doesn't budge despite being stuck with a little piece of 3M adhesive.

Once the lock is installed, you open the Nuki app and get started on the setup. The process is simple: you enter your name and give the app access to location (Android requires this for Bluetooth to work), then you tap and hold the Nuki's central button for 5 seconds to put it in pairing mode and wait for it to be recognized by the app. Then you assign a name to it and a location (for the unlock notification) and tell the app whether you have a knob or handle then make sure your door is unlocked and open. Nuki starts calibrating, which means a full lock and unlock, and you're ready to go. Again, the process is straightforward and took a few minutes to complete. You can see all the corresponding screenshots below.

I picked the knob on the outside, even though our door doesn't have it. Nuki works well without it.

As is, the Nuki works over Bluetooth and requires your phone to be in proximity to communicate with it. You can use a spare phone as a bridge to relay information if you're outside the house (thoughtful feature) or you can purchase a separate Nuki Bridge that acts as a relay from Bluetooth to Wi-Fi to let you control your lock from afar. Unfortunately, the build of the bridge left me a little puzzled. I was told by Nuki that it's been used in another review before and new units are more solid, but I still think the plastic's quality and the sturdiness aren't at the same level as the lock.

Setting up the Nuki Bridge took a little more trial and error. The few steps of plugging the bridge and getting it connected to WiFi were fast, but once it came to pairing with the lock, it just wouldn't happen. That's because I had the bridge installed around the corner from the door, about 5m away. I eventually moved it to another plug about 1.5m away in the kitchen (wall in between) and pairing was successful and everything worked. After that, I moved it again to a third plug also 1.5m away from the door, no walls at all, and that's where it's been for the past month. I figured that was the most optimal location for it. If you plan on using the bridge, I recommend you make sure you have an available plug about 3m away from your door, tops, as I am not the only person to complain about this.

With that out of the way, the Nuki was both directly accessible via Bluetooth and remotely accessible thanks to the bridge.

Security

I am no security expert, so my approach to checking Nuki's security is coming more from a regular user's point-of-view. I see several things working in its favor:

  • The lock is installed inside the door, unlike some brands (Yale, Schlage, Kwikset) which completely replace your lock and show up on the outside. It means would-be thieves can't know that you have a smart lock installed.
  • If you decide not to use the Bridge or the bridge app on a spare phone, your only connection to the lock is via Bluetooth, which means it can't be remotely locked or unlocked.
  • After you've set up everything, you can disable Bluetooth pairing on Nuki from the app so no other devices can pair to it again.
  • You can deactivate any device in case you lose it or it gets stolen.
  • Throughout the entire process, Nuki doesn't ask for an email address, a username, or a password. That only happens when you activate Nuki Web (understandably).
  • The Nuki app and Nuki lock use end-to-end encryption explained in detail here to secure the process of transmitting commands, even if through the Bridge.

However, as the past few months have shown us, nothing is bulletproof. Not WPA2, not Bluetooth, nothing really. I wouldn't call the Nuki impenetrable, but I think the company has done a lot of things right to secure it against different vulnerabilities.

Android app

There are two different Nuki apps for Android. The first, Nuki Smart Lock, is the main app and the one I'll be looking at more extensively below. The second, Nuki Software Bridge, can be installed on a spare phone or tablet you keep around the house, to emulate the Nuki Bridge. You don't need to buy the separate bridge if you don't want to, which is a thoughtful move on Nuki's part. I haven't tried the bridge app, since I have the physical hardware, but the few reviews on the Play Store seem to veer toward the positive.

Nuki Smart Lock
Nuki Smart Lock
Price: Free

Nuki Software Bridge
Nuki Software Bridge

So let's focus on the main app. It is, to be honest, the most impressive part of the Nuki product and it keeps on improving. If €229 seems like too much for a smart lock, it becomes a lot more palatable when you factor in the software and continuous support that need to be provided to make sure your lock keeps on working and even adds more functionality with time.

Main interface

The main interface shows your current locks (I only have one) with a circle similar to the Nuki ring indicating their state. A full circle means locked, an open-top circle means unlocked. You can swipe left and right to quickly change the state of the lock, which is neat but can be prone to accidental actions if you mistake the left-to-right swipe as a gesture to open the side menu. That happened once with me so I disabled the swipe to right gesture.

Door locked (left) and quick menu (right).

Tapping on the screen brings up a quick menu to unlock, lock, open the door (unlock and open the latch), and lock and go (unlock, wait 20 seconds for you to leave, and lock). The last two have a quick info button to see what they exactly mean.

Door counting down in lock and go (left) and info blurb for what opening the door means (right).

Plenty of lock options

The hidden extravaganza of Nuki's options lies within the Settings button you see on the door's menu. That opens up a whole can of worms that took me well over an hour to explore. Every option I thought I'd need, every option I realized I needed after seeing it, and even more options I may never need, all of those are there.

In my work here on Android Police, I come across plenty of first-gen products from companies left and right. More often than not, the app is half-finished, obvious features are missing, and things never work consistently. It's sad, but start-ups feel they can shrug off any criticism under the guise of their freshman status and promise for updates somewhere down the line. As such, it's postively baffling how right the Nuki team got things here and it speaks a lot about the thought going into this product and how serious they are about you entrusting them with the entry to your house. It's proof that you can get started on Kickstarter and deliver a polished product without using it as a free pass.

The main section of a door's settings has three sub-sections for managing the lock, users, and viewing the activity log, but also a few more general settings. These let you change the name, favorite a lock (if you have several), set up smart actions, check its connection status, and choose what happens in the app when you swipe to the left or right.

Main settings for each door lock.

Let's go into some of these. First, the swipe gesture can be assigned to intelligent (lock if it's unlocked, unlock if it's locked), unlock, lock, open, lock 'n' go, or disabled. As I said earlier, I disabled the swipe to right gesture because I made the mistake once of thinking it would open the side menu in the app. Second, the activity log tells you what happened to your lock and through which device.

Smart Action Center (left), Swipe actions (middle), Activity log (right).

Third, the Smart Action Center is where you can set your Nuki to show a notification to open the door when you arrive, auto-unlock when you're near it, and get alerted if you move away and the door is still unlocked. Auto Unlock is the most complex of these and there are several sub-screens of settings for auto-locking afterward, adjusting the geofence size and actions upon exiting it and reentering it and whatnot, and seeing what happened exactly (date and time) when your last auto-unlock occurred. If you like to control every aspect of something, feast your eyes on the granular settings shown below.

All the sub-settings of the Smart Action Center's Auto Unlock feature.

And finally, the connection status screen shows how your Nuki, Bridge, and smartphone are connected. In the screenshots below, my Bridge was connected but still far from the lock (around the corner) and wasn't pairing properly. That's how I knew I had to move it around.

Moving on to the more nitty-gritty of the lock's options, do you remember that "Manage Smart Lock" menu that showed up 4 sets of screenshots above? Yes, that opens up even more settings for managing the lock itself. Here you have about 3 screens worth of options going from simple things like changing the location, time zone, and door fitting, to choosing how much your lock rotates (it automatically calibrated to 720deg for me, since it locks twice), calibrating it again, disabling Bluetooth pairing, updating the lock's firmware, factory resetting the lock, and even controlling how bright the LED light ring on the Nuki's button is. I mean... really?! I love it and I instantly turned it down because it was too bright, but I was not expecting this to be a user-facing choice.

The "Manage Smart Lock" options span 3 screens.

Also among the options are settings to specify whether you're using 4 alkaline AA batteries or rechargeable ones (for determining battery life) and enabling energy-saving for Bluetooth scanning with the app.

Battery type setting (left) and energy saving mode options (right).

The same actions for swiping in the app are available for a simple press or a double press on the physical Nuki button. And you can assign an admin PIN so your account wouldn't get revoked by other users, plus set up the Nuki Web account there.

Press and double-press button options (left), admin pin code (middle), and Nuki Web (right).

As I said, there are so many settings in the app, it took me over an hour to go through and test each one out. I think the organization could use a little improvement as so many screens of black and yellow and white can be difficult to parse quickly, but thankfully you don't have to use this side of the app unless you need to change something. In day-to-day use, none of it is necessary.

User management

The thing to keep in mind is that every device is a user, even Nuki Web, so if you have multiple phones and tablets, you will have to pair or invite them all. That's for the better, I think, and I won't complain despite how many times I had to add and delete users while testing new phones.

However, if there is one aspect of the Nuki that could use a little improvement, it's the user management options. Beside manually pairing a new device with the lock, you can issue invite codes for new users. However, these expire after 48 hours and you can't reuse them so if you have a relative who visits a couple of times a year, you need to delete/add them again each time.

You can enable and disable only a couple of options for each user: revoke their access, locking ability, remote access, and time-limited access. The latter lets you specify start and end dates and specific days and times of the week (for the dog walker or the cleaning staff for example).

 

Users (left) and user management options (right).

However, if you plan on inviting any users you don't trust, absolutely do NOT forget to set up an admin PIN. Without it, every user has access to delete other accounts, view the activity log, and change all of the lock's settings. If you haven't set a PIN, the app should remind you about this every time you invite a new user, but it doesn't. It's the only important thing missing right now in the app.

I would also like to see a bit more granular control over what each user can do and not (disable auto-unlock for the cleaning crew if they also work at the neighbors for example), and for the codes to be re-usable or at least the option to invite the same user repeatedly if they come back often instead of deleting and re-adding them each time.

Other settings

The app drawer on the Nuki app lets you add a new lock, manage the bridge, and access the app's settings. These are super limited: you have the option to play a sound or vibrate each time you unlock the door.

 

Nuki's side menu (left) and app settings (right).

Other things to keep in mind with the Nuki app are that the only permission it requires is Location access, and that you're better off disabling battery optimization for it so that Doze doesn't kill it in the background. With the app not optimized, I found that each time I got home, I'd either get the notification to unlock without touching my phone, or if not, the most I had to do was wake the phone. Nuki would instantly surface the notification then.

Android Wear app

There's a companion Android Wear app that installs on your smartwatch. It works either by connecting to the app on your phone and using that to communicate with the lock, or you can set it up to work directly with the lock by pairing it. Since my phone is often in my pocket, I've often used the Wear app on my watch to open my door and it has worked every time.

  

I didn't take screenshots, but this is exactly how Nuki's Wear app looks.

Nuki Web

If you'd like to do anything with Nuki beyond the app (use it in a browser, connect it to IFTTT, or Assistant, or Alexa), you'll have to set up Nuki Web. This is when Nuki asks you to add an email and password, so that you can use that account to authenticate yourself.

Nuki Web main screen.

The interfaced is similar to the app one, with more whites than blacks. You see your lock(s), the activity log, users, and can control the lock, manage your account, give Web rights to other users, activate API access, and, apparently, integrate with AirBnB. Neat. Oh and you can delete your Nuki account there. If I had a penny for each time I had to email a company to ask them to delete my account because the option wasn't listed on their site, I'd have... about 30 pennies now. Nuki wouldn't be one of them.

Nuki Web lock dashboard (left) and settings menu (right).

One thing I want to see there are my third-party integrations such as Assistant and IFTTT, so I can disable them from the Web interface, on the off-chance that things go haywire with them.

Using Nuki

My husband and I have spent the past month (and a bit more) with Nuki constantly affixed to our door. As I have mentioned a few times already, it has been one of the most reliable "gadgets" in our connected house. It responds to a command from the button instantaneously and from the app in less than a second, it never disconnects for no reason and its Bluetooth doesn't falter, it quickly reconnects when our network is down, and it never once did anything we hadn't asked it to. (Imagine the horror!)

The only downside we see to its usage is its loud sound. You can really hear those gears grinding to twist the key in the lock. In the video below, I opened the door with my phone and you can see and hear how first the key is turned 720-deg then the latch pulled to open the door. When done, I reach out to pull the door to show it's open, but if you pause around the 8th second, you'll also notice how the app has quickly changed the status to "door unlocked."

Other than the sound, everything has been great. We had average expectations going in, we started loving Nuki from the first day and now we rely on it daily. I don't even get my key out of my purse anymore, which means there's less risk of me losing it or misplacing it. Battery life has been good, as far as we can tell. There's no indicator inside the app that I can see, but we haven't had to replace the 4 AA alkaline batteries in over a month of use.

Nuki's physical button is neat when you want to lock/unlock the door manually (intelligent mode) from the inside, and we set a double-press to lock 'n' go so before we go out of the house, we sometimes do it and it automatically locks after 20 seconds. That feels a little long though, a 10-sec option would better suit us since we like to make sure it locked before we take the elevator.

Nuki's open circle light means it's unlocked.

The app has also been updated to add a schedule option, so now we have the Nuki automatically lock the door in the evening, just in case we forgot to do it when we came in. It's funny but it startled us once because we heard Nuki's sound and we thought the door was doing things by itself. Turns out we had forgotten to lock and it was locking at the scheduled time.

Nuki's full circle light means it's locked.

To be completely honest with you, although Nuki advertises the auto-unlock function, we didn't feel comfortable using it. Something about doors opening automatically freaked us out. We did test it out twice though (inadvertently, it's enabled by default on new devices and I had set a new phone twice and forgot to disable it). It worked exactly like promised. The moment I opened the elevator's door and stepped on our landing, my door started unlocking. It's frictionless and completely magical.

The option we felt more comfortable using is the notification. Once we enter the geofence, Nuki surfaces a notification (I've disabled it on the lock screen) with one option to open the door. With a single tap, the door starts unlocking and opening.

 

Nuki's notification settings and Nuki's geofence notification.

Since we don't have any people coming in our house unattended, we tested user management on a couple of spare phones to see how things look for invited users. It worked like expected, despite no direct pairing to the lock. This would have been perfect for us a couple of months ago when we had to drive to the apartment repeatedly several times across a few weeks to let people in and out (my father-in-law was doing some work for us, my parents were dropping a few things). But again, I remind you, if you invite others to your Nuki, absolutely do not forget to set a PIN.

Convenience vs Security

I won't lie to you and say that we're 100% trusting of Nuki. It's a technology after all, and technology is vulnerable and can fail. But then again, I figure if someone is putting all their effort into forcing themselves into your house, a regular lock is just as vulnerable as the Nuki. Perhaps more.

My experience with the product so far says that the team behind it isn't taking the security of your apartment lightly and is doing a great job at keeping everything as secure, as smooth, and as fail-proof as possible. That eases my fears a little. It also helps that I still never leave the house without my regular key and can still open my door with it, if Nuki goes berserk one day.

But to my husband and me, the benefits of Nuki come in several levels that outweigh the nagging paranoid voice in our head. First, it's neat to know the state of our door's lock remotely and to have a detailed log of each lock/unlock/and open action. Second, it's convenient to be able to lock and unlock the door without using our key, which means less risk of losing or misplacing it. Since our phone/watch is already in/on our hand, it also means less things to carry and drop when we're arriving or leaving. Third, it's safer to schedule the door to lock each night should we forget, and it's effortless to ask Assistant if the door is locked when we go to bed, and lock it if it isn't.

Fourth, it puts our mind at ease to know that, should we absolutely need to, in case of emergency or special circumstances, we can let family, friends, and people in remotely, without having to drive to the house or ask them to break the door. I imagine this can be more useful if you have kids dropping from school. And finally, if we have a guest staying over, we can easily invite them to use Nuki for a short period of time then revoke their access.

Smart home integrations

What's a smart gadget if it can't integrate with other smart gadgets in your house? After setting up Nuki Web, you can add it to your IFTTT channels and control it via Assistant and Alexa.

Google Assistant

Nuki has an Actions-on-Google integration with Assistant (it doesn't show up in Home Control and it uses a different voice than Google's). I think Assistant still doesn't have native support for locks like it does for lights and thermostats, so this isn't Nuki's fault. The downsides are that unlocking isn't possible (not even with a PIN), you'll have to "talk to Nuki" to ask it anything, and each user will need to link their Assistant to Nuki separately. Thankfully, you can set up voice shortcuts that make more sense to you, like "is the door locked" = "ask Nuki for the state." But, again, these only work for your voice. Every user will have to add the same shortcuts, which... ugh Google!

You can lock Nuki with a voice command, ask for the current state of your lock, and ask for the activity log or who locked the door, which gives you a detailed report of the last 5 actions. These are super handy when you're lying in bed at night and don't want to jump up and run to the door to check that it's locked.

Others

I don't have an Echo in my house, so I didn't test Alexa, but Nuki has a skill for it that you can read about here and check on Amazon here. Unlike Assistant, this one also lets you unlock/open the door, but requires a PIN to verify it's you before it does, for security reasons.

Nuki also has an IFTTT channel with plenty of granular triggers and actions. Since the Nuki app doesn't notify me when someone else unlocks the door, I set up an IFTTT applet to do that and tell me who (or what) exactly did it. I also have my LiFX lights breathe when we're near the door to notify people inside that someone is coming and not startle them with the sound of the lock spinning.

We also started using an applet to lock the door with our Google Home when walking out of the apartment. Since lock 'n' go takes 20 seconds and since the Assistant integration is voice specific and needs to be set for everyone, we did it through IFTTT. Now we just say, "Hey Google, lock the door" before going out, close the door, and Home answers back "Prison mode activated" and locks Nuki. You can also add an applet to unlock or open the door with Google Home and I tested it to make sure it works, but since there's no PIN or voice match for protection with IFTTT, I removed it.

The missing link is direct integration with SmartThings and Wink (and other smart home hubs). Someone seems to have built a working solution for SmartThings, and you can do some things with IFTTT, but a direct integration with an official device handler would be great. That way you could use the recently added option to issue temporary invite codes for locks from the SmartThings app and monitor the state of your door directly through it.

Conclusion

The sticker price on Nuki is shocking, I can't refute that. But when you factor in the support period required afterwards with continuous software updates to the app and firmware updates to the lock, you realize that the lock costs more than it does because you're paying for that added service and for the company to keep its lights on and your product to keep working. Plenty of smart home companies nowadays are closing shop (see Emberlight) or charging for a monthly fee afterwards (see LiftMaster and Chamberlain) to add new features because it's not sustainable for them to keep providing a service for free. I'm not saying Nuki won't, but for now, all the features and updates have been free and the company is working toward monetization with apartment buildings (Nuki Box) and service deliveries.

Even if you agree to the price, the security question is something only you can answer for yourself and your household. So is the "need," utility, and value of something that seems as extravagant as a smart lock. But all things considered, Nuki has done a kick-ass job of tightening all the security holes I could think of and giving you a real-world advantage to using its lock.

Plus, the hardware is solid, the installation is easy, the app is filled to the brim with options you need and ones you may never use, and I had to be really picky to find only a few settings missing in it. Though given the frequent updates, I wouldn't be surprised if these were added soon. And most importantly, the system works reliably. Whether you're using auto-unlock, the notification, your watch, or your phone, the door opens when you need it to. Voice commands plus IFTTT integration make it even smarter.

If you have a Euro Profile Cylinder lock, your options are extremely limited when it comes to a smart door lock. There's Danalock (a quick look at the app and ratings made me run away), eLocky but you can't use a regular key with it, a few crowdfunding projects but you'll have to wait and pray for something good (Teodoor), Tesa Abloy's ENTR looks impressive and adds a door sensor but the app is terrible and hasn't been updated in 22 months (yay for support!), then there are the locks that integrate with a whole smart home setup (Somfy and so on) but compatibility and even the apps are questionable in that case. By comparison, Nuki offers a polished product start to finish and is easily the one I'd purchase.

BuyNuki lock + bridge combo €299 (Nuki, Amazon.fr, Amazon.de, Amazon.co.uk)

Buy: Nuki lock €229 (NukiAmazon.fr, Amazon.de, Amazon.co.uk)