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Aqara Smart Lock U400 vs Eufy FamiLock S3

Full Smart Door Locks comparison in 2026

Updated October 2026
Data from Amazon and 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.
Aqara Smart Lock U400
Winner
Aqara Smart Lock U400
$269.99

Last recorded price

Buy on Amazon USA
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.
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FeatureAqara Smart Lock U400Eufy FamiLock S3Winner
Price$269.99$349.99Aqara Smart Lock U400
Rating4.14.0Aqara Smart Lock U400
Battery Life6 months4 monthsAqara Smart Lock U400
ConnectivityBluetooth, Thread Protocol, Other2.4 GHz WiFiAqara Smart Lock U400
Lock/Unlock SystemRemote, Bluetooth, Passcode, Fingerprint, NFC Tag, Apple Home Key, Physical KeyRemote, Passcode, Physical KeyAqara Smart Lock U400
DoorbellNOYESEufy FamiLock S3
Weather ResistanceIP65IP65Tie
IntegrationsGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterTie
One-Time PasswordYESYESTie
Periodic PasswordYESYESTie
Anti-peep PasswordYESYESTie
Emergency FingerprintNONOTie

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
  • Eufy FamiLock S3

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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 $269.99, while Eufy FamiLock S3 lists $349.99.

Which one looks better on price?

Aqara Smart Lock U400 is listed at $269.99, while Eufy FamiLock S3 is listed at $349.99. 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.

Full comparison table

Compare all 52 Door Locks side by side

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  • 52 Door Locks
  • 55 specs compared
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