Door Locks · Head to head

Aqara Smart Lock U400 vs Nuki Smart Lock Go

Full Smart Door Locks comparison in 2026

Updated October 2026
Data from Amazon and official Aqara and Nuki sites.
2026 verdict
Approaching an Apple Home door, the Aqara Smart Lock U400 is the smart lock that can open hands-free.
Aqara Smart Lock U400
Winner
Aqara Smart Lock U400
$269.99

Last recorded price

Buy on Amazon USA
It is a full deadbolt with IP65 sealing, ultra-wideband approach unlock, fingerprint, NFC, Apple Home Key and a keypad, on a rechargeable pack rated about 6 months, with Matter over Thread, one-time codes, periodic codes and anti-peep entry. The Nuki Smart Lock Go is an indoor European-cylinder retrofit, not weather rated, with phone unlock, geolocation and Matter, while a keypad or fingerprint means an accessory and remote access is a one-time purchase. They do not fit the same door. Buy the Aqara Smart Lock U400 to replace a deadbolt. Keep the Nuki Smart Lock Go only to leave a euro cylinder in place.
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FeatureAqara Smart Lock U400Nuki Smart Lock GoWinner
Rating4.13.8Aqara Smart Lock U400
Weather ResistanceIP65NOAqara Smart Lock U400
Lock/Unlock SystemRemote, Bluetooth, Passcode, Fingerprint, NFC Tag, Apple Home Key, Physical KeyRemote, Bluetooth, Passcode, Fingerprint, Physical KeyAqara Smart Lock U400
One-Time PasswordYESKeypad requiredAqara Smart Lock U400
Periodic PasswordYESKeypad requiredAqara Smart Lock U400
Anti-peep PasswordYESNOAqara Smart Lock U400
ConnectivityBluetooth, Thread Protocol, Other2.4 GHz WiFi, Bluetooth, Thread ProtocolTie
IntegrationsGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterTie
Emergency FingerprintNONOTie
DoorbellNONOTie

What the differences mean

Deadbolt or cylinder retrofit

The Aqara Smart Lock U400 replaces the deadbolt, with the keypad and reader on the outside. The Nuki Smart Lock Go clamps over a European cylinder and leaves that cylinder in place, which is why renters look at it. It is not a US deadbolt. If the bore is a standard deadbolt, the U400 is the one that matches. If the door is a euro cylinder you cannot change, the Go is the one that matches.

Ways in

The Aqara Smart Lock U400 includes fingerprint, a keypad, NFC, Apple Home Key, a physical key and ultra-wideband approach unlock, plus one-time, periodic and anti-peep codes. The Nuki Smart Lock Go unlocks by phone, geolocation and the existing key. Passcode and fingerprint are accessories, and anti-peep entry is marked not supported. Hands-free on the U400 is the UWB walk-up. Hands-free on the Go is geolocation.

Weather

The Aqara Smart Lock U400 is IP65. The Nuki Smart Lock Go is not weather rated. An exterior door that takes rain is a U400 fact, and only if that door accepts a full deadbolt. The Go stays an indoor retrofit. Do not stretch it to an exposed cylinder just because the other lock is sealed.

Remote access

The Aqara Smart Lock U400 lists remote unlock as supported, over Matter and Thread, with a Thread border router in the picture for that path. The Nuki Smart Lock Go lists 2.4 GHz Wi-Fi and Thread as well, and its remote unlock line is a one-time purchase. Local Bluetooth works on the Go without that purchase. Away-from-home control is the line to budget.

Which one to buy if

Winner
Aqara

Aqara Smart Lock U400

Prime exclusive deal
$269.99

Last recorded price

Buy on Amazon USA
  • + Rating: 4.1
  • + Weather Resistance: IP65
  • + Lock/Unlock System: Remote, Bluetooth, Passcode, Fingerprint, NFC Tag, Apple Home Key, Physical Key

What owners say

Owners praise different kinds of convenience, and they worry about different failures. Aqara Smart Lock U400 owners lead with ultra-wideband unlock that opens the door as they walk up, a motor they call quicker than older deadbolts they replaced, and a USB-C pack they can top up. They also call the housing plasticky for the price, the first Home setup confusing, and the approach unlock less than perfect for everyone. Nuki Smart Lock Go owners single out a tool-free mount over an existing cylinder, which renters like, and hands-free locking when they arrive with bags. Their hard complaints are motor errors within the first year and AA cells that can swell, with support that replaces units, plus a paid add-on before remote control feels complete.

Price history compared

Every price change of both, in the same store, so the gap between the two lines is what one costs more than the other.

  • Aqara Smart Lock U400
  • Nuki Smart Lock Go

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Frequently Asked Questions

Which is better overall: Aqara Smart Lock U400 or Nuki Smart Lock Go?

The Aqara Smart Lock U400. It takes the scored rows: weather sealing, the unlock methods, guest-code tools and owner reception. The Nuki Smart Lock Go is still the retrofit for a European cylinder you are not allowed to replace.

What is the biggest difference between the Aqara Smart Lock U400 and the Nuki Smart Lock Go?

Form. The Aqara Smart Lock U400 replaces a deadbolt and adds fingerprint, NFC, Apple Home Key and IP65 sealing. The Nuki Smart Lock Go mounts on a European cylinder, keeps the existing key, and treats a keypad as an accessory.

Does the Nuki Smart Lock Go work with Apple Home?

Yes. The Nuki Smart Lock Go supports Apple Home, Google, Alexa, SmartThings, Home Assistant and Matter over Thread. Apple Home Key is not supported. The Aqara Smart Lock U400 supports those platforms and Apple Home Key, and its write-up says Google and Alexa need an Aqara hub even though the sheet marks them supported.

Is the Nuki Smart Lock Go a US deadbolt?

No. It is a retrofit for a European cylinder. The Aqara Smart Lock U400 is the full deadbolt replacement in this pair, with a keypad and fingerprint reader on the outside.

Who should buy the Aqara Smart Lock U400?

Apple households replacing a deadbolt who want ultra-wideband approach unlock, Home Key, fingerprint and an IP65 exterior.

Who should buy the Nuki Smart Lock Go?

Renters and euro-cylinder doors that must keep the existing lock, who want phone and geolocation unlock and can add a keypad later, knowing remote access is a one-time purchase.

Full comparison table

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