iOS 18 Hands-Free Smart Lock Proximity

Apple introduced hands-free smart lock unlocking in iOS 18, allowing compatible door locks to open automatically as you approach without requiring a physical tap. This article covers the specific proximity threshold required to trigger this feature, the underlying Ultra-Wideband (UWB) technology, and the directional requirements necessary to prevent unintended entries.

The Hands-Free Proximity Threshold

In iOS 18, hands-free smart lock unlocking triggers when a compatible device is within approximately 0.5 to 1 meter (about 1.5 to 3 feet) of the lock.

Unlike traditional Bluetooth-based proximity systems, which estimate distance based on signal strength (RSSI) and often suffer from wide variances, iOS 18 utilizes Ultra-Wideband (UWB) chips to achieve centimeter-level spatial accuracy. The system requires you to be directly at the threshold of the entryway before initiating the unlock command.

Directional Awareness and Movement

Distance alone does not trigger the unlocking mechanism. The UWB integration tracks spatial vectoring to ensure security:

  • Approach Trajectory: The lock triggers only when the user is actively approaching the exterior of the door.
  • Inside vs. Outside Detection: The system distinguishes whether the device is inside the home or outside. Walking past the door inside your house will not trigger an unlock, even if you are well within the 1-meter radius.
  • Stationary Presence: Lingering near the door without approaching directly can suppress the unlock command to prevent accidental openings.

Hardware and Software Requirements

To utilize hands-free unlocking at this proximity threshold, your setup must meet specific criteria:

  1. Operating System: iOS 18 or watchOS 11.
  2. Device Support: An iPhone with Apple's U1 or U2 Ultra-Wideband chip (iPhone 11 or later, excluding iPhone SE models) or an Apple Watch with UWB (Apple Watch Series 6 or later, excluding Apple Watch SE models).
  3. Lock Hardware: A smart lock equipped with native UWB radios and support for Apple Home Key's hands-free specification (often aligned with the Aliro smart access standard). Older Home Key locks that rely strictly on NFC still require tapping the device against the reader.