Yale Linus L2 vs Nuki: which smart lock should you buy?

The decision in one line: keep your cylinder, or swap it

Yale and Nuki sell the same idea in different boxes: a motor that turns the lock from the inside of your front door, controlled from a phone, a keypad or a smart-home hub. The real choice is not the badge. It is whether the lock fits over the cylinder you already have, so your existing key keeps working, or replaces that cylinder with the maker’s own.

The Yale Linus L2 and Nuki’s Smart Lock Pro (5th Gen) and Smart Lock Go are all retrofits: Yale says the L2 keeps your physical key in use with an included thumbturn adapter, and Nuki lists the Pro and Go as fitting over existing cylinders. The Nuki Smart Lock Ultra is different: it requires a cylinder change and comes with Nuki’s own Universal Cylinder. If your door already has a cylinder your insurer is happy with, that one fact narrows the field more than any spec sheet. Our smart locks comparison covers the other locks we track.

Linus vs Linus L2: what Yale changed

Three Yale locks carry the Linus name, so be sure which one you are buying. The original Linus, which Yale’s UK support pages list at 58 × 58 × 150mm and 623g with batteries, runs on four replaceable batteries. The Linus L2 has, in Yale’s words, in-built Wi-Fi and Bluetooth, so remote locking from the Yale Home app needs no bridge, and a rechargeable pack charged over USB-C. Yale’s getting-started FAQ gives it as 51.7 × 146.2 × 45.75mm without the thumbturn and 648g. If an original Linus of yours used Yale’s Connect Wi-Fi Bridge, Yale’s support page says that bridge controls one lock at a time.

Then there is the Linus L2 Lite. Yale’s own comparison table shows the Lite running on three CR123A batteries, needing the separately sold ConnectX Wi-Fi Bridge for remote control and scheduled locking, and fitting lift-to-lock doors only; the Yale Dot comes in the L2 box but is sold separately for the Lite. Everything in this guide about the L2 is about the full L2, not the Lite.

Fit and installation: what each maker says your door needs

The Linus L2 fits over the inside thumbturn of your existing cylinder, using the thumbturn adapter in the box, so your key keeps working. Yale’s FAQ adds that a 22mm round or Swiss cylinder can be fitted with an included adhesive backer, and Yale sells the L2 with a backplate handle for multipoint doors with handles, or a cradle pull escutcheon for euro mortice and auto-engage doors. Yale recommends upgrading to its 3 Star cylinder, but the L2 does not require it. Run Yale’s compatibility checker, linked from its product pages, before ordering.

Nuki’s retrofits work the same way: the Go clamps over the existing lock with no drilling and no cylinder change, and Nuki lists the Pro (5th Gen) as compatible with existing cylinders. The Ultra swaps your cylinder for Nuki’s Universal Cylinder, so its compatibility guide is about your door: no more than 68mm from the cylinder’s retaining screw to the inner door plate and 55mm to the outer one, with extensions sold for longer outer lengths. A new cylinder means new keys for everyone, worth knowing if a neighbour or relative holds one now.

Both makers’ locks sit on the inside of the door. Nuki’s Ultra page gives it as the smallest and fastest Nuki at ⌀57 × 58mm, against ⌀57 × 70mm for the Pro (5th Gen) and 110 × 60 × 60mm for the Go; the L2 is a longer 146mm bar. Nuki’s guides for the Ultra and Go ask for more than 30mm from the keyhole centre to both the frame and the handle on an inward-opening door, and 40mm to the frame on an outward-opening one. On a narrow door, measure before you buy.

Connectivity: Wi-Fi, Matter and the bridge question

None of the three front-runners needs a bridge. Yale’s L2 has in-built Wi-Fi and Bluetooth, and Nuki lists built-in Wi-Fi with remote access included on the Pro (5th Gen) and Ultra. The Go is the exception: Nuki’s comparison lists remote access as a separate purchase, so out of the box it is a Bluetooth lock you operate near the door, with keypad codes letting others in when you are not there.

On Matter, Yale lists Matter hubs from Apple, Google, Amazon and Samsung SmartThings for the L2, and says Matter 1.2’s separate “Unlock” and “Open Door” actions currently work with Home Assistant as the hub. With Wi-Fi and Bluetooth as its radios, the L2 uses Matter over Wi-Fi. Yale adds that older L2 units lack the Matter code in their QR label and are set up with a code from the Yale Home app. Nuki lists Matter over Thread on the Pro (5th Gen) and Ultra, and Matter on the Go; over Thread, your Matter hub must also be a Thread border router. Check what you own first.

Subscriptions: Yale’s plan table puts lock control, push and email notifications, unlimited users and smart-home integrations on its free plan; the paid plans add cloud recording, cellular backup and monitoring for Yale’s cameras and alarms. On the Nuki side, the extra cost to know about is remote access for the Go, which Nuki sells separately; the Pro (5th Gen) and Ultra include it.

Batteries, keypads and door sensors

The L2 uses a built-in rechargeable pack charged over USB-C; Yale quotes up to six months per charge, a one-to-five-hour charge time depending on the charger and battery level, a recommended 5V 1–3A charger, low-battery indicators in the Yale Home app, and sells a replacement pack. Nuki’s Pro (5th Gen) and Ultra also have built-in rechargeable batteries, and Nuki says both recharge in about two hours on or off the door. The Go instead takes four AA batteries, included, which some households prefer because a flat lock is fixed with a trip to the kitchen drawer rather than a cable.

Keypads are extras on all but the Go bundle. Yale’s Smart Keypad takes 4–6 digit codes per user and connects to the lock over Bluetooth at roughly three metres; its Smart Fingerprint Keypad adds fingerprint entry, one-touch locking and a built-in doorbell, and Yale sells L2 bundles with either. Nuki’s Keypad 2 opens the door by fingerprint or code, and the Keypad 2 NFC adds NFC; the Smart Lock Go bundle on our pages comes with Nuki’s Keypad, which Nuki says stores up to 200 codes.

Door sensing differs. Yale’s comparison table lists the Yale Dot as included in the L2 box, with DoorSense, so the lock can tell you whether the door is shut as well as locked. Nuki sells its Door Sensor as a separate accessory. If “did I close the door?” is the question you most often ask from the office, the L2 answers it without another purchase.

Insurance and standards: what neither maker claims

The motor unit on the inside of your door is not a lock in the sense your insurer means; the cylinder and the mechanism in the door are. Yale makes no BS 3621, TS 007 or Sold Secure claim for the Linus L2 unit on its UK product pages; it points instead to its separately sold 3 Star cylinder. Nuki makes no BS 3621 or Sold Secure claim for the Ultra or its Universal Cylinder, so if your policy names one of those standards, nothing Nuki publishes shows that the Ultra’s cylinder meets it.

So the practical rule is this. With a retrofit (Linus L2, Nuki Pro, Nuki Go), whatever rating your existing cylinder carries stays in place underneath, and your key still works. With the Ultra, the cylinder your insurer may have asked about is removed and replaced with Nuki’s. Before buying either, read your policy’s lock wording, look for the Kitemark or TS 007 stars on your current cylinder, and if the Ultra tempts you, ask your insurer in writing whether a change of cylinder matters. A smart lock does nothing for the windows: window locks and door and window alarms cover the rest of the house.

Getting out in a hurry: fire and failure

A front-door lock must still let everyone leave quickly, in the dark, without a phone. Before fitting any of these, read the maker’s instructions for opening the lock by hand from the inside, then try it with the lights off, and make sure every member of the household, including children and older relatives, can do it. A retrofit keeps your existing cylinder and key; the Ultra’s Universal Cylinder comes with its own keys. In a block of flats, ask your landlord or managing agent before fitting anything to the front door, and never fit a smart lock to a shared escape route.

Keep a spare key somewhere a trusted person can reach, and, as the government’s Fire Kills campaign advises, keep door keys where everyone can find them in the dark. Our house fire guide covers the escape plan every household should rehearse; a key safe is the usual answer for carers and relatives who need in when the app does not.

Who should pick which

Pick the Yale Linus L2 if you want a retrofit with Wi-Fi built in, a door sensor in the box, Matter over Wi-Fi for Apple, Google, Amazon or SmartThings hubs, and Yale’s fingerprint keypad as an option. It keeps your cylinder and key exactly as they are, and Yale sells it with a backplate handle or a pull escutcheon for multipoint, euro mortice and auto-engage doors.

Pick the Nuki Smart Lock Pro (5th Gen) if you want the same keep-your-cylinder approach with Matter over Thread and Nuki’s two-hour recharge figure, and you already run a Thread border router. It is the closest like-for-like to the L2 and the comparison most searchers are really making. It is not in the live price cards below, because Amazon’s price feed stopped returning its UK listing in September; check Nuki’s own shop.

Pick the Nuki Smart Lock Ultra if you are happy to replace your cylinder, want the smallest unit and want everything built in. Just do the insurance check first. Pick the Nuki Smart Lock Go with Keypad if codes for family, a cleaner or a dog-walker matter more than unlocking from your desk, you prefer AA batteries, and you want Nuki’s entry-level lock with a keypad in the box; add Nuki’s remote access later if you find you miss it.