August Wi-Fi Smart Lock - Best Retrofit Smart Lock

The August Wi-Fi Smart Lock is the definitive choice for a retrofit smart lock, designed to augment an existing deadbolt rather than replace it. This approach offers significant advantages: installation is straightforward, typically requiring only a screwdriver and a few minutes, and it preserves the existing keyway and keys, making it perfect for rental properties or those who like their current hardware. Despite its add-on nature, it doesn't skimp on features. It provides built-in Wi-Fi for remote access, comprehensive activity logs, and the ability to create and manage temporary guest access passes—a boon for hosts or allowing access to service providers. The included DoorSense module attaches to the door frame to detect whether the door is open or closed, enabling accurate auto-lock schedules and sending alerts if the door is left ajar.

Compatibility is broad, working with Amazon Alexa, Google Assistant, and Apple Home. The main trade-offs are aesthetic and maintenance-related. The interior unit is bulkier than a standard thumb turn, and its rechargeable battery pack needs to be topped up every few months, unlike locks with multi-year disposable batteries. Some users also report that the auto-unlock feature, which uses geofencing to unlock as you approach, can be inconsistent. For those seeking a non-invasive, feature-rich way to modernize their door security, the August Wi-Fi Smart Lock remains a top-tier and highly convenient option.