Aqara U400: How UWB unlocking works

The Aqara Smart Lock U400 is a deadbolt lock announced at CES 2026. Its distinguishing feature is hands-free UWB unlocking: with an authorized, compatible device, the lock can detect the user’s approach and unlock without requiring them to tap a phone on the reader or enter a code.

The practical difference is the gesture it removes, not the need for authentication: access remains tied to configured devices and permissions. Aqara also offers alternative entry methods, so proximity unlocking is not the only way to get in.

CES was the setting for the announcement, not a future launch date. Aqara announced the U400, and its launch offer on the company’s forum initially covered the United States and Canada. That does not mean the lock is generally available in every country or that a particular variant is sold locally.

The U400 uses UWB (ultra-wideband) for hands-free unlocking. According to Aqara, a compatible phone or watch can remain in a pocket while the lock detects an authorized approach and unlocks. The lock also offers NFC access, along with other options.

For UWB unlocking, Aqara’s product page specifies an iPhone 11 or later, excluding iPhone SE and iPhone 16e, running iOS 18.5 or later; or an Apple Watch Series 6 or later, excluding Apple Watch SE, running watchOS 11.5 or later. A Thread-compatible Apple Home hub is also required. Check the exact requirements before buying: having a recent iPhone alone does not guarantee the feature will work.

The U400 uses Matter over Thread to integrate with compatible smart-home platforms. Matter helps devices from different brands communicate, but it does not remove each ecosystem’s requirements: Aqara says a Thread-enabled Matter controller is needed for the relevant platform.

In addition to UWB unlocking, Aqara lists Apple Home Key, a fingerprint reader, keypad passcodes, app control, an optional NFC card and a physical key. These methods provide alternatives to proximity unlocking.

When choosing a platform, consider two separate questions: whether the lock can join the ecosystem through Matter, and whether that ecosystem supports each advanced feature. Automatic UWB unlocking and Apple Home Key have specific requirements; they are not guaranteed simply because the product mentions Matter, Thread or platform compatibility.

The U400 is a deadbolt. Before replacing a lock, check the model’s documentation for deadbolt type and dimensions, door thickness, available clearance and installation orientation. Physical fit matters: Matter does not determine whether the deadbolt fits a particular door.

Aqara describes a removable, rechargeable battery that charges via USB-C. The product page rates battery life at up to six months per charge; this is a stated maximum, not a guarantee for every household. Usage, unlocking frequency, connectivity and settings can affect how often the battery needs charging.

A physical key and alternative entry methods matter with a connected lock. Before installation, decide who will manage passcodes and credentials, keep the backup key somewhere accessible and check how the system warns about a low battery. The U400 also has app-configurable features, so the experience can vary depending on whether you use Aqara’s software.

Unlocking as someone approaches replaces a deliberate action, such as entering a PIN or tapping a reader, with presence detection. The U400 also offers other access methods, including fingerprint, passcode, NFC and a physical key.

Use unique administrator passwords, limit shared permissions and keep the lock and smart-home devices updated. For temporary access, check its expiration and revoke it when it is no longer needed.

The U400 is marketed for outdoor use, and Aqara’s product page lists an IP65 rating for the exterior portion. This rating should not be taken to mean every part of the lock can be exposed to any conditions: follow the installation instructions and distinguish the exposed side of the door from the interior side.

The CES 2026 announcement is in the past. Aqara introduced the lock and announced its launch; subsequent announcements and listings indicate that it is commercially available in some markets. Availability is not universal: the country, retailer and variant can differ, and sales in North America do not establish official distribution in Spain or Latin America.

Aqara’s product page is the reference for checking features, but the price should be confirmed with a seller in the intended market, along with the warranty, taxes and return terms. A price listed by a retailer in another country does not establish the final local cost without accounting for import charges and after-sales support.

Before buying, check the deadbolt’s physical fit on your door and confirm that your phone or watch meets the UWB requirements. For the smart-home features you plan to use, also check whether you have a suitable Thread controller. Confirm the final price, warranty and support terms with a local retailer.