Aqara UWB Smart Lock U400: A Smart Lock That Unlocks Before You Reach the Door
Most smart locks still expect you to pull out your phone, tap a fingerprint reader, or enter a code. The Aqara UWB Smart Lock U400 goes further by using Ultra-Wideband technology to recognize your approach and unlock automatically, making entry feel closer to walking through an automatic door than operating a lock.
Features Worth Paying Attention To
UWB Unlocking Reduces Everyday Friction
Unlike Bluetooth proximity unlocking, UWB detects both distance and movement direction, helping prevent accidental activation while allowing the door to unlock naturally as you arrive.
Multiple Backup Entry Methods
Fingerprint, touchscreen PIN, Apple Home Key, app control, voice assistants, NFC cards, and a physical key ensure you still have access if one method becomes unavailable.
Matter Over Thread Improves Compatibility
The U400 works across Apple Home, Alexa, Google Home, and Home Assistant through Matter over Thread, avoiding dependence on a single ecosystem while benefiting from faster and more stable local communication.
Rechargeable Instead of Disposable Batteries
The removable battery is rated for up to six months of use and can be recharged through USB-C without removing the lock from service.
Questions Many Buyers Have
Q1: Can UWB unlocking work without an Apple Home hub?
A: No. It requires a compatible Thread-enabled Apple hub.
Q2: Does fingerprint unlocking still work if Wi-Fi is down?
A: Yes. Fingerprint authentication is processed locally.
Q3: Can family members use different unlock methods?
A: Yes. Each user can choose fingerprints, passcodes, Apple Home Key, or other supported options.
Q4: Is it suitable for outdoor exposure?
A: Yes. The exterior carries an IP65 weather-resistance rating.
Q5: What happens when the battery runs low?
A: Voice alerts warn below 20%, and USB-C charging can restore power without removing the lock.
Overall Perspective
The U400's biggest advantage is not fingerprint access or app control—many competitors offer those. Its real distinction is UWB hands-free unlocking combined with Matter over Thread support, creating an entry experience that requires almost no deliberate action while remaining compatible with multiple smart home platforms.
- Additional Features: UWB True Hands-Free Unlock
- Lock Type: Deadbolt
- Control Method: App
- Connectivity Protocol: Matter
- Smart Home Compatibility: Smart Home Compatible
- Shape: Rectangular
- Controller Type: Amazon Alexa, Apple HomeKit, Google Assistant, Home Assistant, SmartThings