The Good: Good looks, strong user management, and convenient automated features make the August Smart Lock a leader in its niche. The Bad: Android users don't get auto-unlock at launch, Bluetooth can cause irritating connection lag, you can't control the August Smart Lock over Wi-Fi without a separate hub and at $250 it's one of the most expensive smart locks available. The Bottom Line: We haven't seen a flawless smart lock yet, but the August Smart Lock comes closer than any of its competitors thanks to its ease of use and overall polish. Editor's note, Feb. 13, 2015: This review has been updated to account for the August Connect WiFi accessory.Editor's Note, Aug. 20, 2020: In August 2020, PCMag and Bitdefender released a report alleging that August and Yale Android apps when working with Connect modules were vulnerable to a hack during setup mode that could give away Wi-Fi credentials. In August's latest response to CNET, it states, "If the Connect's firmware is up-to-date and the user's August Android app is up-to-date, their device will not be vulnerable to the original attack even if the unit enters into setup mode." The following review was published prior to this report and has not been altered.The August Smart Lock nails most of the things I'd want in a connected door lock. It's easy to install. It looks good (yes, despite its size) and the August app (in iOS, at least) gives you the right balance between flexibility and keeping things safe and simple. The fact that it works with your existing deadbolt is also a plus.The $250 asking price (international availability pending) puts August on the more expensive end of the smart-lock spectrum. The August Smart Lock also suffers from the same limitations as other connected locks. Because it's a Bluetooth-only device, controlling the lock with your phone when you're out of range requires either a compatible third-party hub or August's new $50 Connect accessory that you'll need to buy separately. Bluetooth also means you'll suffer from minor but still annoying lag when you first open the app to interact with the Smart Lock.If the lag means you won't likely swap your physical key out for the August and a connected smartphone, this lock still gets enough things right that it's become our new favorite automated door control. We will certainly see more connected locks come to market over the next few years. This is the one they need to beat.Not like other locksWe've reviewed a handful smart locks , and all of them but August involve wholesale replacement of your lock hardware. In the case of the August Smart Lock, it's designed to use your existing deadbolt and keyset, replacing only the thumbturn on the inside face of your door.For the most part the complete lock sets have been fine, but we ran into trouble when we reviewed the Kwikset Kevo . The Bluetooth-based functions of that lock work well enough, but the deadbolt is not as secure as the company claimed. As we said in our review last year, the Kevo's Bluetooth tech is impressive, but the product as a whole suffers since you can't separate it from the lock hardware.Because the August is a retrofit product, the quality of the deadbolt is up to you. As long as your existing lock uses one of the 100 or so compatible deadbolts on this list, you can add the August lock to it.Easy installationRead the directions with your August lock to make sure you match up the various pieces of mounting hardware with your existing deadbolt, but overall installation is simple and should only take about 15 minutes.Essentially, you take off the thumbturn, and use your lock's existing screws to attach the August mounting plate and adapter to your door. To hang the August lock itself on the mounting plate, you lift up two little "wings" on each side of the lock, situate the lock on the plate, and the push the wings down to hold the lock in place.In theory this installation should be simple, and if you align everything correctly it will be. If it doesn't all slide together easiler, you'll be tempted to push the lock in hard and force the wings down if you don't get a perfect fit at first. Don't. I broke one August by turning it too hard. If it doesn't latch on to the plate easily, start over.Once you install the lock, or likely even after you take it out of the box, you'll notice that it's big. At almost 2.25 inches thick and 3.25 inches across, it's smaller than the boxy control units that come with most of the other smart locks we've seen, but between its size and its unique shape, August gives a bulky first impression.I got used to its looks after a few days. There's a certain Duplo-inflected charm to its stubby, over-sized appearance. The silver case and the line pattern etched into the finish also look good (black, red, and "champagne gold" options also available). I also like that the metal ring around the lock functions as a mechanical turn for the deadbolt. It's crucial that any smart lock performs its basic lock\/unlock functions regardless of whether it has power. August's approach does that well.You use four included AA batteries to power the August. To connect it to your phone, download the August app, turn on Bluetooth, and follow the software walkthrough. It works with iOS 7-plus-based devices from the iPhone 4S forward, and with any Android 4.4 or greater-based device that also has low-power Bluetooth. The only difference between the two versions is that Android lacks a handy auto-unlock feature. August tells us it's working on adding it to Android in a future update.User managementDuring set up you'll create an account and manage a "Keychain" designed to handle multiple locks. You can name each lock, and if your account is dubbed the "Owner," you can manage all of the settings and distribute e-keys to anyone with a compatible smartphone or tablet.August carves out an advantage for itself with its free, unlimited e-key distribution policy. Kwikset and other smart-lock makers charge you per key once you go past a certain allotment. That approach has always felt stingy, and I'm glad to see August expose it as such.