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Our hands-on verdict on the 4th-gen retrofit smart deadbolt that keeps your existing keys
Who it's for: renters and homeowners who want keyless, app-controlled entry without replacing their existing deadbolt or losing their keys.
This assessment is editorial and based on hands-on testing combined with research into manufacturer specs, owner feedback and independent reports. Lock specs, ratings and ecosystem support change often — verify the current details on the retailer's page before you buy.
The August Wi-Fi Smart Lock is the easiest way to go keyless without commitment. Because it mounts on the inside of your existing deadbolt, your door looks unchanged from the street and everyone keeps their physical keys. That makes it the rare smart lock a renter can install and take with them — a ten-minute, screwdriver-only job.
In daily use it's the convenience features that win you over. Auto-unlock reliably senses your arrival and lets you in hands-free, DoorSense tells you whether the door is actually shut and locked (not just bolted into thin air), and built-in Wi-Fi means remote control and notifications work with no extra bridge cluttering an outlet. HomeKit, Alexa and Google support are all here, so it slots into whichever ecosystem you already use.
On security, August publishes a BHMA AAA rating, but the honest framing is this: the lock is only as strong as the deadbolt it drives, so pair it with a solid ANSI/BHMA Grade 1 or Grade 2 deadbolt. The real trade-offs are practical — there's no keypad in the box (you add the August Keypad for code entry), and the compact battery pack needs recharging or fresh cells more often than chunkier keypad deadbolts.
| Type | Retrofit smart deadbolt (interior mount) |
| Connectivity | Built-in Wi-Fi + Bluetooth (no bridge) |
| Security rating | BHMA AAA; pair with ANSI/BHMA Grade 1–2 deadbolt |
| Keypad | Optional (August Keypad sold separately) |
| Power | Rechargeable / replaceable battery pack |
| Smart home | Alexa, Google Assistant, Apple HomeKit |
| Key features | Auto-unlock, DoorSense, guest access, activity log |
| Install | ~10 min, screwdriver only, keeps existing keys |
| Indicative price | ~$150 (lock unit) |
A full deadbolt replacement with a built-in keypad, ANSI/BHMA Grade 1 build and Apple Home Key tap-to-unlock. The pick if you want maximum lock strength and a keypad in one unit.
View on AmazonA versatile deadbolt sold in keypad and key-free trims with swappable Wi-Fi/Z-Wave/HomeKit modules. Great if you want to match the connectivity to your hub and like a sleek touchscreen.
View on AmazonWant the full picture? See how the August lock compares head-to-head in our best smart locks comparison →
No — and that is the point. It retrofits onto the interior side of your existing deadbolt, so you keep your current keys and exterior hardware. Anyone outside still uses a normal key while you get keyless app control inside. Installation takes about 10 minutes with a screwdriver.
No. The 4th-gen August Wi-Fi Smart Lock has Wi-Fi built in, so remote lock/unlock, auto-unlock and notifications work without the older Connect bridge. It also uses Bluetooth for fast local control when your phone is nearby.
August publishes a BHMA AAA rating for its smart lock, and because it works with your existing deadbolt, the real-world security still depends on that deadbolt — pair it with an ANSI/BHMA Grade 1 or Grade 2 deadbolt for the best protection. Data is protected with bank-level encryption.
Yes. The 4th-gen lock supports Amazon Alexa, Google Assistant and Apple HomeKit, so you can lock, unlock (with a PIN) and check status by voice or from each platform's app. Auto-unlock detects your arrival and lets you in hands-free.
