Smart Door Locks
Aqara’s Thread lock: Apple Home Key, NFC, fingerprint, keypad, auto-unlock and a door sensor, Matter over Thread, no cloud account or subscription, and BHMA certified (grade not stated). The rechargeable pack is rated at 6 months by Aqara. No Wi-Fi, so you need a Thread border router.
#3 of 5 smart door locks
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The Aqara Smart Lock U400 beats the category average in 4 of 5 areas.
It beats the category average in 4 of 5 areas.
| Spec | Smart Lock U400 | Against the rest |
|---|---|---|
| Thread Low-power mesh used by Matter. Needs a Thread border router (HomePod mini, Nest Hub, SkyConnect…). | Yes | beats 75% |
| Cloud account required You must create a manufacturer account to set it up. Some devices stop working if the cloud shuts down. | No | beats 67% |
| Door sensor Knows if the door is open or closed, not just locked. | Yes | beats 50% |
| Matter Works with every major platform locally. Check which device types are supported — some features may stay app-only. | Yes | beats 50% |
| Spec | Smart Lock U400 | Against the rest |
|---|---|---|
| Battery life Manufacturer estimate at ~8 operations per day. Wi-Fi locks drain faster than Thread or Bluetooth. | 6 months | behind 80% |
Aqara Smart Lock U100
70
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ULTRALOQ Bolt SE
65
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Aqara Smart Lock U400
61
TP-Link Tapo DL110
47
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eufy Smart Lock C220
24
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Score 61 vs 53 category average · 7 of 7 scored specs known. How we score
“Works with Alexa” can mean full local control or a cloud skill that only switches it on. Here’s which one.
20 of 21 specs sourced
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Unlock methods Auto-unlock uses your phone's location. Fingerprint and keypad work without a phone, useful for kids and guests. | AppKeypadFingerprintNFCApple Home KeyAuto-unlock | Manufacturer spec sheet | |
| Auto-lock Locks itself after the door closes. Works best with a door sensor. | Yes | Manufacturer spec sheet | |
| Door sensor Knows if the door is open or closed, not just locked. | Yes | Manufacturer spec sheet | beats 50% |
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Installation Retrofit locks sit on the inside and keep your existing key. Renters usually want retrofit. | Full lock replacement | Manufacturer spec sheet | |
| Lock standard Euro profile cylinders are common in DE, NL, FR and the Baltics. Check the emergency function on your cylinder. | US deadbolt | Manufacturer spec sheet | |
| Security certification Independent tests such as SKG (NL), VdS (DE) or ANSI/BHMA (US). | BHMA certified (grade not stated) | Manufacturer spec sheet |
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Battery life Manufacturer estimate at ~8 operations per day. Wi-Fi locks drain faster than Thread or Bluetooth. | 6 months | Manufacturer spec sheet | behind 80% |
| Battery Rechargeable packs are convenient but the lock is offline while charging unless you have a spare. | Rechargeable pack | Manufacturer spec sheet |
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Wi-Fi 2.4 GHz has longer range. Dual band helps in crowded apartment buildings. | No | User manual | |
| Thread Low-power mesh used by Matter. Needs a Thread border router (HomePod mini, Nest Hub, SkyConnect…). | Yes | User manual | beats 75% |
| Zigbee Mature mesh protocol. Works locally with Zigbee2MQTT or ZHA in Home Assistant. | No | User manual | beats 0% |
| Bluetooth Usually only for setup or short-range control. | Yes | User manual |
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Matter Works with every major platform locally. Check which device types are supported — some features may stay app-only. | Yes | Manufacturer spec sheet | beats 50% |
| Home Assistant Core integrations ship with Home Assistant. HACS integrations are community-maintained and can break after updates. | Matter | Manufacturer spec sheet | |
| Alexa | Yes | Manufacturer spec sheet | |
| Google Home | Yes | Manufacturer spec sheet | |
| Apple Home | Yes | Manufacturer spec sheet | beats 40% |
| Spec | Smart Lock U400 | Source | vs all smart door locks |
|---|---|---|---|
| Works offline Keeps working with your internet down — schedules, automations and local apps still run. | Yes | Home Assistant docs | |
| Cloud account required You must create a manufacturer account to set it up. Some devices stop working if the cloud shuts down. | No | User manual | beats 67% |
| Subscription for key features Features locked behind a monthly fee, e.g. history, AI detection or remote access. | No | Manufacturer spec sheet | |
| Firmware updates via HA Update the firmware from Home Assistant without the vendor app (Zigbee2MQTT OTA, Matter OTA). | ? Not published |
Published by Aqara. We check these links every week.
Buy from the Amazon store in your country.
| Region | Buy |
|---|---|
| US for you | from $269.99 |
| UK | Buy at |
Price as of 4 Nov 2026 · amazon.com
Smart Lock U100$149.99
Encode$229.31
Assure Lock 2 Keypad with Wi-Fi
$195.22$259.99
Tapo DL110$149.99
Smart Lock U100$149.99
Didn’t find your answer? Ask us
Yes. Schedules and local control keep working offline; only remote access needs the internet.
Yes, via Matter. See the setup steps above.
Yes, so it pairs locally with Apple Home, Google Home, Alexa, SmartThings and Home Assistant.
No. All features work without a subscription.
The US version (), sold on amazon.com. Other regions use different plugs and model numbers — see “Variants” above.
The Aqara manufacturer’s warranty for your region. In the UK and EU you also have statutory rights against the seller; check the listing on Amazon for details.
