Winner
15% OFF
Prime exclusive deal$229.49
$269.99
Join Prime to buy it at $229.49
Updated October 2026
Data from the official Aqara and Eufy sites.
2026 verdict
Aqara Smart Lock U400 has the better all-around case than Eufy FamiLock S3 in 2026, starting with price, rating, and battery life.
It builds its lead on price, rating, and battery life, then backs it up with a stronger showing on connectivity and Lock/Unlock system. The only strong reason to choose Eufy FamiLock S3 is if doorbell is more important to you than the overall verdict. That is why the final call still favors Aqara Smart Lock U400.
vs
20% OFF
$279.98
$349.99
Connectivity
- Wi-Fi 2.4 GHz
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| Feature | Aqara Smart Lock U400 | Eufy FamiLock S3 | Winner |
|---|---|---|---|
| Price | $229.49 | $279.98 | Aqara Smart Lock U400 |
| Rating | 4.1 | 4.0 | Aqara Smart Lock U400 |
| Battery Life | 6 months | 4 months | Aqara Smart Lock U400 |
| Connectivity | Bluetooth, Thread Protocol, Other | 2.4 GHz WiFi | Aqara Smart Lock U400 |
| Lock/Unlock System | Remote, Bluetooth, Passcode, Fingerprint, NFC Tag, Apple Home Key, Physical Key | Remote, Passcode, Physical Key | Aqara Smart Lock U400 |
| Doorbell | NO | YES | Eufy FamiLock S3 |
| Weather Resistance | IP65 | IP65 | Tie |
| Integrations | Google Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, Matter | Google Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, Matter | Tie |
| One-Time Password | YES | YES | Tie |
| Periodic Password | YES | YES | Tie |
| Anti-peep Password | YES | YES | Tie |
| Emergency Fingerprint | NO | NO | Tie |
Winner
15% OFF
Prime exclusive deal$229.49
$269.99
- + Price: $229.49
- + Rating: 4.1
- + Battery Life: 6 months
- - Doorbell: NO vs YES
20% OFF
$279.98
$349.99
- + Doorbell: YES
- - Price: $279.98 vs $229.49
- - Rating: 4.0 vs 4.1
Frequently Asked Questions
Which is better overall: Aqara Smart Lock U400 or Eufy FamiLock S3?
Aqara Smart Lock U400 has the stronger overall profile in this comparison, especially for price, rating, and battery life.
What is the biggest difference between Aqara Smart Lock U400 and Eufy FamiLock S3?
Price is one of the clearest differences: Aqara Smart Lock U400 lists $229.49, while Eufy FamiLock S3 lists $279.98.
Which one looks better on price?
Aqara Smart Lock U400 is listed at $229.49, while Eufy FamiLock S3 is listed at $279.98. Aqara Smart Lock U400 (better spec).
Who should buy Aqara Smart Lock U400?
Choose Aqara Smart Lock U400 if your priority is price and rating and that matters more than doorbell.
Who should buy Eufy FamiLock S3?
Choose Eufy FamiLock S3 if your priority is doorbell and that matters more than price.
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Compare all 55 Door Locks side by side
You are looking at two of them. The full table lines up all Door Locks in the catalog with the same specs, so you can filter by what you need and sort by price or rating.
- 55 Door Locks
- 55 specs compared
- 51 filters
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FamiLock E40
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Lock Vision
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U-Bolt Pro WiFi
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Smart Lock C220
- Air Quality Monitors
TVOC Air Quality Monitor
- Buttons
Cube T1 Pro
- Buttons
Wireless Mini Switch T1
- Buttons
Wireless Mini Switch WXKG11LM
- Cameras
Camera E1
- Cameras
Camera G100
- Cameras
Camera Hub G2H Pro
- Cameras
Camera Hub G3
- Cameras
Camera Hub G350
- Cameras
Camera Hub G5 Pro PoE
- Cameras
Camera Hub G5 Pro WiFi
- Ceiling Lights
Ceiling Light T1M
- Doorbells
Doorbell Camera G400 (Wired)
- Doorbells
Doorbell Camera Hub G410
- Doorbells
Smart Video Doorbell G4
- Door Locks
Smart Lock D200i
- Door Locks
Smart Lock N100 Zigbee Edition
- Door Locks
Smart Lock U100
- Door Locks
Smart Lock U200
- Door Locks
Smart Lock U300
- Cameras
4G Camera S230
- Cameras
4G LTE Cam S330
- Cameras
Cam S3 Pro
- Cameras
Cam S330
- Cameras
Cam S4
- Cameras
eufyCam C37
- Cameras
Indoor Cam C120
- Cameras
Indoor Cam E220
- Cameras
Indoor Cam E30
- Cameras
Outdoor Cam E210
- Cameras
Outdoor Cam E220
- Cameras
PoE Bullet-PTZ Cam E50
- Cameras
SoloCam E30
- Cameras
SoloCam E42
- Cameras
SoloCam S220
- Cameras
SoloCam S230
- Cameras
SoloCam S340
- Cameras
TrackLight Cam S1
- Cameras
Wall Light Cam S4
- Cameras
Window Camera E10