Here at DRN we endeavour to spend some actual time using products before we work on the review, this one took me a little longer but I’m glad I spent the time! Aqara make some seriously sexy (if I may) gear, right out of the box with all of the hardware you’ll need to go about your install, even into an old Victorian door like mine.
I’ve had a month or so living with the Aqara U400 and I’m 99% sure it’s the best smart lock for home that I could have on my front door! I’ve listed below that it’s a straightforward install, I do want to point out that I’ve removed the Aqara U100 (and relocated it to my back door) to install the U400 in my front door – for the sake of transparency, I did have one small issue, my security screen door is very close to my VERY old front door and, with the U400 being larger than the U100, I made the decision to shift it down the door a little, so it was effectively a whole new install for me!
I’d also add that UWB is SO good! Walking up to the door and having it click green and open the lock is excellent – there have been a couple of times when I’ve had to do a quick shimmy (phone in my back pocket) to make the U400 do the magic, but that speaks to the proximity you need to get the iPhone (and soon / now Android) to shake hands… I’ve had ZERO false-positives or random unlocks.
The Pitch: Truly Hands-Free Entry via UWB
Smart locks have been making big promises for a long time. Unlock with your phone. Unlock with your fingerprint. Unlock from anywhere in the world. The technology has improved steadily, but in practice it has always required you to do something — tap, press, scan, wait for Bluetooth to stop pretending it was asleep. The Aqara Smart Lock U400 changes the equation in a meaningful way: it uses Ultra-Wideband (UWB) technology to detect your approach and simply unlocks the door as you walk up to it. No interaction required. Hands full of shopping? Doesn’t matter. Phone buried at the bottom of a bag? Doesn’t matter. It just opens.
That single feature is either the most compelling thing in a smart lock right now, or an expensive party trick depending on your setup. After daily use, I’d lean firmly toward the former — with a couple of honest asterisks.
Design & Build: Modern Aesthetics Meets IP65 Durability
The U400 is unambiguously a smart lock — it won’t be mistaken for the deadbolt your parents had in 1994. The footprint is larger than a conventional lock, with a touchpad on the exterior and a clean, modern interior assembly. It’s available in both black and silver, giving you a reasonable choice to match your door hardware. The overall aesthetic is understated and handsome in either finish — it doesn’t try to show off, which for something you look at every time you come home is actually the right call.
Build quality feels solid, The hardware carries an IP65 rating on the exterior assembly, meaning it handles rain, dust, and the general indignity of being a door lock without complaint. It’s BHMA Grade 3 certified — Grade 3 is the entry-level of the three certification tiers, and some competing locks achieve Grade 2, but in everyday residential terms the practical difference is minimal.
Installation: A Straightforward DIY Retrofit
Installation was straightforward, though granted, I’m a little bit of a DIY’er at heart, but still… With a regular door setup, the U400 is a retrofit deadbolt replacement — you’re fitting it in place of an existing single-cylinder deadbolt, and the process follows the same steps you’d expect: remove the old hardware, thread the new assembly through the bore, connect the interior and exterior components, and secure everything in place. The included instructions are clear, the hardware is well packaged, and nothing in the process required professional help or specialist tools. From box to working lock is a comfortable one-person job.
The U400 is available as a standalone lock or bundled with the Aqara M100 USB Smart Hub — a compact Thread border router that provides the connectivity backbone needed for UWB unlocking if you don’t already have a compatible hub in your setup. In my case, I already had a HomePod mini acting as my Thread border router, along with several other Aqara devices on the network, so the M100 stayed in the box. But for anyone starting fresh or without an Apple home hub, it’s a useful inclusion that removes one potential sticking point from setup.
Software setup via Apple Home was seamless. Matter over Thread means the lock pairs directly into the ecosystem without being forced through Aqara’s app, and enabling Express Mode for UWB unlocking took about two minutes.
Aqara U400 Technical Specifications
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Wireless |
Matter over Thread, Bluetooth 5.2, NFC, UWB |
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Fingerprints |
Up to 50 (98.6% accuracy rated) |
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PIN codes |
Up to 75 (6–10 digits) |
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Users |
100 via Aqara / 20 via Matter |
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Battery |
Rechargeable Li-ion, approx. 6 months |
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Charging |
USB-C (in-lock port or removable pack) |
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Weather rating |
IP65 (exterior) |
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BHMA rating |
Grade 3 |
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Colour options |
Black, Silver |
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In the box (kit) |
Lock + Aqara M100 USB Smart Hub |
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Ecosystems |
Apple Home, Google Home, Alexa, SmartThings, Home Assistant |
Why Ultra-Wideband (UWB) Beats Geofencing
UWB is not geofencing. Geofencing uses GPS and covers a wide radius — sometimes unlocking your door when you’re still a street away, which makes most people quietly disable it after a week. UWB is precise down to centimetres, using radio-based ranging to pinpoint your device’s distance and angle relative to the lock. The result is a lock that genuinely understands when you’re approaching your front door — not just somewhere in the general vicinity.
“You walk up to the door and it unlocks. After a week of it, going back to any other method feels like a step backwards.”
In daily use, the UWB unlocking has been the single most friction-reducing addition to my home. The reaction time is excellent — the lock is open by the time your hand reaches the handle. The system also handles multiple family members cleanly via Apple Wallet digital keys, and the lock distinguishes between authorised devices reliably.
One genuine caveat: as of now, UWB auto-unlocking is exclusive to Apple users. It requires a compatible iPhone (Series 11 or later, excluding SE models) or Apple Watch, plus an Apple home hub — HomePod mini, HomePod 2nd gen, or Apple TV 4K — serving as the Thread border router. The Aliro standard, the open cross-platform version of this feature, is coming and the U400 is listed as Aliro-ready, but it hasn’t fully arrived yet. For a pure Apple household this isn’t an issue at all. For a mixed household, it’s worth knowing before you buy.
Reliable Access: Fingerprint, PIN, and App Control
The fingerprint reader is built into the exterior and works quickly and reliably. Aqara rates it at 98.6% accuracy, and in practice it’s fast enough to feel immediate — a brief press and you’re in. The reader stores up to 50 fingerprints, covering a family and a handful of regular guests without trouble. For visitors without an enrolled print, the PIN code (6–10 digits) works just as cleanly, and the touchpad illuminates well in low light.
App unlock via Apple Home or the Aqara app works as expected — useful for letting in a tradesperson when you’re away, checking lock status at a glance, or locking remotely if you’ve left in a hurry. Night Latch Mode (admin and physical key only after a set time), Auto Lock, and Do Not Disturb for overnight quiet are all available when you want them. Nothing requires configuration out of the box.
Battery Life: Sustainable Power via USB-C
The U400 runs on a rechargeable lithium-ion battery — a genuine departure from the AA rotation that smart lock ownership has historically involved. Aqara rates it at around six months per charge, and a low-battery notification fires at 20%, giving you plenty of runway. Charging is via USB-C, either in-lock through a port on the interior assembly, or by removing the battery pack entirely. There’s also an emergency external USB-C port on the exterior for the rare scenario where you’ve let it run flat — power it temporarily with a phone charger or power bank to get yourself in.
The rechargeable approach is both more convenient and better for the environment than cycling through disposable batteries. The only trade-off is that “charge it every six months” requires slightly more intentionality — but the notification system handles the reminder well.
Security Standards and Matter Integration
From a digital security standpoint, Matter over Thread is a strong foundation — local communication, no reliance on a cloud server going down at an inconvenient moment, and encrypted data transmission throughout. The lock activity log is accessible via Apple Home or the Aqara app, giving you a clear record of who came and went and when. Access management is flexible: through Aqara’s system you can manage up to 100 users across admin, standard, and temporary roles. Via Matter alone the ceiling is 20 users — plenty for a family home, though worth noting for more complex arrangements.
Speaking of security, when I close my door, the U400 locks – its actuation is faster than my U100, which works well for this door, here’s an example;
Considerations: BHMA Ratings and Aliro Support
The U400 carries a BHMA Grade 3 certification — the entry level of three tiers. For most residential applications this is entirely sufficient, but some competing smart locks achieve Grade 2. The broader security picture is reassuring: multi-factor authentication options, UWB precision (no false unlocks from across the street), encrypted communication, and full activity logging all contribute to a well-rounded setup. The cylinder can also be rekeyed if needed without replacing the whole lock assembly.
Verdict: The Most Compelling Smart Lock in 2026
The Aqara U400 is the most compelling smart lock available right now, and the UWB hands-free unlocking is the reason. Not as a gimmick — as a genuine daily quality-of-life improvement that, once you’ve lived with it, makes every other method feel laborious by comparison. Installation is clean, the fingerprint reader is fast and reliable, the battery system is sensible, and the Matter over Thread foundation means it plays well with practically every smart home ecosystem.
The kit version bundled with the M100 USB Hub makes for a complete out-of-the-box setup for those without an existing Thread border router, while Apple household users with a HomePod or Apple TV 4K can skip straight to configuring. The two honest caveats — UWB currently being Apple-only until Aliro arrives (1.0 specification release in early 2026), and the BHMA Grade 3 certification sitting at the lower end of the residential scale — are real but neither is a dealbreaker for the intended audience. Available in black or silver to suit your door hardware, and firmly worth the investment.
Gold star, Aqara, the U400 is a beautiful thing.
The Aqara U400 is on pre-sale now from their website, available in black or silver with RRP A$549.00. Right now it’s down to A$459.
DRN would like to thank Aqara for providing the review unit. And it’s get a DRN Pulse Award, congratulations!
