Tech

How Ultra Wideband Is Revolutionizing Smart Locks for iPhone and Apple Watch

Feb 3rd 2026

AI-generated, human-reviewed.

The latest advances in smart home security now allow you to unlock your front door automatically, simply by approaching with your iPhone or Apple Watch—no tapping or extra app required. On iOS Today, Stephen Robles shared his first impressions of the Aqara U400 (affiliate link) Smart Lock, the first smart lock designed to leverage Apple’s Ultra Wideband (UWB) chip for truly reliable proximity-based unlocking.

Why Aqara’s U400 Lock Is a Standout for Apple Users

Apple wasn’t present at CES 2026, but its ecosystem was everywhere thanks to accessory makers like Aqara, who are pushing boundaries in smart home integration. The Aqara U400 is the first smart lock to take full advantage of the Ultra Wideband chip in iPhones and Apple Watches, delivering instant and secure hands-free unlocking without needing to tap a device or rely on unpredictable Bluetooth connections.

Stephen Robles found that, unlike earlier locks which used unreliable Bluetooth proximity (sometimes unlocking when you’re near the inside of the door), UWB now enables granular, location-aware unlocking. Users can set rules for which approach angles will unlock the door, such as “left,” “right,” or “center,” all directly in the Apple Home app with no need to use Aqara’s own app.

Pros & Cons

Pros:

  • True proximity unlock: The lock can unlock as you approach with your iPhone or Apple Watch, no manual interaction needed.
  • Location-aware controls: Easily customize which directions trigger unlocking (left/right/center) for added security.
  • Apple Watch support: Even if your iPhone is in the car, your Apple Watch alone can trigger unlocking.
  • Reliable operation: UWB eliminates unreliable Bluetooth triggers and lock mishaps.
  • Multiple unlock methods: Still supports tapping with Home Key, fingerprints, PIN codes, and app-based controls.

Cons:

  • Fingerprint setup requires Aqara’s app: You can program fingerprints only via Aqara’s app, rather than natively in HomeKit.
  • Some advanced features still in development: For instance, HomeKit Secure Video is capped at 1080p (not 2K/4K).

What Makes UWB Different From Bluetooth in Smart Locks?

Ultra Wideband (UWB) is a newer wireless technology included in recent iPhones and Apple Watches. Unlike Bluetooth, UWB measures spatial location accurately, which means your lock knows when you’re outside, inside, approaching, or just passing by. Previous smart locks relying on Bluetooth could randomly unlock when you were inside near the door; Aqara’s U400, by using UWB, avoids accidental unlocking, making it much safer for families or shared homes.

Who Is the Aqara U400 For?

This lock is ideal for:

  • Apple users with an iPhone or Apple Watch featuring UWB support (recent models)
  • Anyone seeking hands-free home entry without unreliable workaround apps
  • HomeKit enthusiasts who want granular control in Apple’s native app
  • People looking for a lock that supports multiple unlock modes—biometric, PIN, or tap

However, if you prefer fingerprint-only unlocking or need compatibility outside the US, check with Aqara and see if the newest features work in your region.

Key Takeaways

  • The Aqara U400 is the first smart lock bringing true hands-free unlocking to Apple users with UWB-equipped devices.
  • Set your own unlock rules in the Apple Home app, improving convenience and security.
  • UWB delivers much greater reliability and control than old Bluetooth-based proximity locks.
  • Multiple unlock methods are supported: proximity, tap, fingerprint, or PIN.
  • Some advanced features, such as full biometric setup, still require using Aqara’s app. But general control remains HomeKit-friendly.

If you’re an Apple user who wants a more intuitive, reliable, and customizable smart lock, the Aqara U400 (affiliate link) is a best-in-class pick. Ultra Wideband integration means you don’t have to fumble for your phone, worry about failed unlocks, or deal with confusing third-party apps. Check compatibility with your devices, consider geographic availability, and give your home a security upgrade with Apple’s latest technology.

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https://twit.tv/shows/ios-today/episodes/787

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