Advertiser Disclosure

Aqara U300 Smart Lock Review: Retrofit Convenience

John Carter Doe

October 1, 2025

8.8

Very Good

Is the Aqara U300 the right smart lock for you?

Here's the quick take.

Look, if you're just trying to make your existing deadbolt smart without a bunch of drama, the Aqara U300 is honestly one of the safest bets you can make. It's what's called a retrofit lock, meaning it just attaches to the inside of your door. Your outside lock and your old keys? They stay exactly the same. And here's the thing: it uses Matter over Thread, so it'll play nice with pretty much any smart home system, and it doesn't need to phone home to the cloud for its basic functions. Day-to-day, it's just plain reliable and a total lifesaver for renters. Just know that if you want to use PIN codes or a fingerprint, you'll need to grab Aqara's separate wireless keypad. And it doesn't do Apple Home Key—for that, you'd need to look at its sibling, the Aqara U100.

Is the Aqara U300 the right smart lock for you?

What you'll love... and what you should know.

The biggest win here is that retrofit design. Because it only goes on the inside, you keep your home's curb appeal and, more importantly, your original keys. That's a huge plus for anyone renting or dealing with a strict HOA. Then you've got the Matter over Thread support, which gives you snappy, local control that feels really polished. You don't even need an Aqara hub for the core features. But, believe it or not, it's not perfect. The motor isn't loud, but you'll definitely hear it. And, as with any smart lock, the auto-unlock feature is only as good as your phone's location services, which can be hit-or-miss.

So here's my final thought. The Aqara U300 absolutely nails it for anyone who wants an easy-to-install, super-flexible, and dependable retrofit lock. It just works. Now, if you're dead set on tapping your iPhone or Apple Watch to unlock your door (that's Apple Home Key), then yeah, you'll want to check out the Aqara U100 instead. But honestly? For most people who just want to add smarts to their door without swapping out all their hardware, I'd tell you to go for the U300. It's the one I'd recommend to a friend.