I need a smart lock that works with my existing deadbolt hardware.

Yes — you want a retrofit smart lock, which mounts on the inside of your existing deadbolt rather than replacing the whole deadbolt. Your existing key and exterior hardware can stay unchanged.

Here are the ones I'd consider:

• August Wi-Fi Smart Lock - $199.99 (The Home Depot)

• SwitchBot Lock Pro - $119.99 (Best Buy)

• Yale Approach Retrofit Smart Lock - $140.99 (Wayfair)

• Level Bolt (Matter) - $199.00 (The Home Depot)

• August Wi-Fi Smart Lock — My safest all-around recommendation. It fits over the inside of your existing deadbolt, keeps your physical keys working, and has Wi-Fi built in, so you don't need a separate hub.

• SwitchBot Lock Pro — Best if you're worried about compatibility. Its adjustable mounting system supports a particularly broad range of existing deadbolts; Matter support is available with the Hub Mini.

• Yale Approach — A good alternative if you want to stay in the Yale/​August ecosystem, with optional keypad/fingerprint accessories. It also installs on the inside of the existing deadbolt.

• Level Bolt (Matter) — Best if you want the smart-lock hardware essentially invisible. Instead of adding a large mechanism over the thumbturn, it installs inside the door and preserves the existing exterior hardware.

The important part: compatibility depends on your exact deadbolt — especially whether it's a single-cylinder deadbolt, the thumbturn shape, and the door/lock dimensions.

If you tell me the brand/model of your current deadbolt (or send me a photo of the inside and outside of the lock), I can narrow this down to the best 1–2 locks that will actually fit, including current prices.

The Yale Approach Smart Deadbolt Go to product viewer dialog for this item. and SwitchBot Lock Pro Go to product viewer dialog for this item. attach to your existing interior deadbolt hardware so you can keep your current exterior keys.

Top Retrofit Smart Locks

Popular Options

Add to list Installs on the inside of your door while leaving the outside hardware completely untouched.

Add to list Universally adapts to most standard US deadbolts with an easy rear-mounted magnetic/adhesive or screw setup.

Add to list Replaces just the interior thumbturn of most standard single-cylinder deadbolts with a compact round design.

If you'd like, tell me:

• What brand of deadbolt do you currently have?
• Do you need Wi-Fi remote access or just Bluetooth/auto-unlock?

I can help you pick the exact model that fits your setup.

Yes — you want a retrofit smart lock, which installs on the inside of your existing deadbolt rather than replacing the whole deadbolt. Your existing key and exterior hardware can stay in place.

Here are the ones I'd look at:

• SwitchBot Lock Pro - $119.99 (Best Buy)

• August Wi-Fi Smart Lock - $199.99 (The Home Depot)

• Level Bolt (Matter) - $199.00 (The Home Depot)

• Yale Approach Retrofit Smart Lock - $197.26 (The Home Depot)

• SwitchBot Lock Pro — best overall value. It fits a particularly broad range of existing deadbolts and can add Matter compatibility through the Hub Mini. Current listing is around $120.

• August Wi-Fi Smart Lock — easiest/safest bet. It mounts over the interior thumb-turn, keeps your existing key working, and has Wi-Fi built in, so you don't need a separate hub.

• Level Bolt (Matter) — best if you want it invisible. The mechanism goes inside the door/deadbolt, so the finished lock looks essentially unchanged from the outside and inside.

• Yale Approach — good if you want a retrofit plus keypad/fingerprint options. It installs on the inside of the existing deadbolt while retaining your keys.

My default recommendation: I'd pick the SwitchBot Lock Pro if compatibility and value matter most, or August if you want the simplest, most established retrofit setup.

One important caveat: retrofit locks aren't universally compatible with every deadbolt. If you send me a photo of the inside of your door showing the deadbolt/thumb-turn, I can tell you which of these should fit and narrow it down to the best one.

If you want to keep your exterior deadbolt hardware and original physical keys , you need an interior retrofit smart lock . These devices replace only the thumbturn on the inside of your door, leaving the outside looking entirely unchanged.

The top options on the market depend on how you want it to look and connect:

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• How it works: Replaces just the interior escutcheon and thumbturn of your existing single-cylinder deadbolt.
• The exterior: Completely unchanged; your old key works just like it always did.
• Smart features: Built-in Wi-Fi and Bluetooth, auto-unlock/auto-lock via DoorSense, and optional Bluetooth/biometric keypads. You can check out options directly via Yale Home.

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• How it works: A classic, cylindrical retrofit design that mounts directly over your existing interior thumbturn setup.
• The exterior: Untouched, preserving your current keys and exterior style.
• Smart features: Built-in Wi-Fi, auto-unlock when you arrive, and integration with major smart home platforms.

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• How it works: Unlike locks that sit on top of the door, the Level Bolt actually replaces the internal mechanical bolt mechanism itself inside the door.
• The exterior: 100% invisible from both the inside and outside. It retains your exact exterior faceplate and original key.
• Smart features: Operates on Matter-over-Thread for smooth integration with Apple Home, Google Home, and Alexa. You can view details on the Level Home Store.

Add to list

• How it works: A retrofit design that mounts onto your existing interior cylinder/key setup.
• The exterior: Preserves your outside hardware and key.
• Smart features: Uses Matter-over-Thread and supports fingerprint access, PIN codes, and Apple Home Key via an included wireless keypad.

To help narrow down the best fit, let me know:

• Which smart home ecosystem do you use (Apple Home, Google Home, or Alexa)?
• Do you prefer an interior-only module or one that includes an external keypad / fingerprint reader?

Yes — you want a retrofit smart lock, which replaces/turns the interior mechanism while leaving your existing exterior deadbolt and key in place.

My top picks

August Wi-Fi Smart Lock

$199.99

SwitchBot Lock Pro

$119.99

Yale Approach Lock with Wi-Fi and Keypad

$179.99

Level Bolt (Matter)

$199.99

• Best overall: August Wi-Fi Smart Lock — a proven retrofit that installs over your existing deadbolt, keeps your exterior hardware/key, and has built-in Wi-Fi, so you don't need a separate hub. Current listing is about $200.
• Best value: SwitchBot Lock Pro — about $120 in the current listing and designed specifically to fit existing deadbolts. It can add Matter support through a SwitchBot Hub 2.
• Best if you want a keypad: Yale Approach — retrofit design that keeps your existing keys, with versions including a keypad and Wi-Fi.
• Most discreet: Level Bolt (Matter) — the mechanism installs inside the door, so it preserves the appearance of your existing lock and keys.

One important caveat: retrofit compatibility depends on the exact deadbolt. If you tell me the brand/model of your existing deadbolt (e.g., Schlage, Kwikset, Defiant) and whether you want Apple Home, Google Home, Alexa, or just phone control, I can narrow it down to the best compatible option.

If you want to keep your exterior hardware and original keys, you need an interior retrofit smart lock (which replaces only the inside thumb-turn) or an invisible cylinder replacement.

Top options that work with your existing deadbolt hardware include:

• How it works : Replaces just the interior thumb-turn using a screwdriver; leaves the exterior deadbolt and key completely untouched.

• Pros : Exceptional smart home compatibility (Alexa, Google, Apple Home), built-in Wi-Fi (no separate hub needed), and renter-friendly.

• Cons : Slightly bulky cylindrical design on the inside of the door.

• How it works : Installs completely inside your existing standard deadbolt mechanism.

• Pros : 100% invisible from both the inside and outside; your door looks and operates entirely normally until triggered electronically.

• Cons : Limited to specific deadbolt brands/models; check their Level Compatibility Guide before buying.

• How it works : A slim, low-profile interior adapter that mounts over most standard single-cylinder deadbolts.

• Pros : Sleek aesthetics, smooth motor, comes bundled with an optional wireless keypad, and reliable auto-unlock/auto-lock via DoorSense.

• Cons : Relies on Bluetooth/Wi-Fi connection via Yale's app ecosystem.

• How it works : Attaches over your current thumb-turn via strong adhesive or a custom mounting bracket.

• Pros : Extremely broad compatibility with various deadbolt shapes, fast torque, and physical tactile button options.

• Cons : Adds a noticeable box to the interior side of the door.

To help narrow down the best fit , tell me:

• What brand is your current deadbolt (e.g., Schlage, Kwikset)?
• Do you prefer an invisible look (like Level Bolt) or an app/keypad combo (like August or Yale)?

Yes — you want a retrofit smart lock, which operates your existing deadbolt from the inside instead of replacing the whole deadbolt. That lets you keep your existing exterior hardware and physical key.

My top picks

August Wi-Fi Smart Lock

$199.99

SwitchBot Lock Pro

$119.99

Yale Approach Lock with Wi-Fi and Keypad

$179.99

Level Bolt (Matter)

$199.99

1. August Wi-Fi Smart Lock — best all-around

• Attaches to the inside of your existing deadbolt.
• Keeps your existing key and exterior hardware.
• Built-in Wi-Fi, so no separate hub is needed.
• Supports Apple Home, Alexa and Google Home.
• Current listed price I found: about $200.

2. SwitchBot Lock Pro — best value

• Retrofit design with no need to replace the deadbolt.
• Around $120 currently.
• Particularly attractive if you want a relatively inexpensive retrofit and don't mind using a separate hub for some smart-home features.

3. Yale Approach — best if you want a keypad

• Retrofit installation preserves your existing deadbolt.
• Available with a Wi-Fi bridge and keypad, including a fingerprint-capable version.
• A good choice if you want guests/family to enter with a code rather than an app.

4. Level Bolt (Matter) — best if you want the lock to remain essentially invisible

• Installs inside the existing deadbolt mechanism rather than putting a large motor on the interior.
• Keeps your existing keys and exterior appearance.
• The newer Matter version supports Apple, Alexa, Google and SmartThings.

One important catch

Compatibility depends on the exact deadbolt, especially whether it's a single-cylinder deadbolt with an interior thumb-turn and enough clearance around it. The retrofit products don't universally fit every deadbolt.

If you tell me your deadbolt brand/model (Schlage, Kwikset, Weiser, etc.), or send me a photo of the inside and outside of your lock, I can narrow this down to the models that should actually fit.

If you want to keep your exterior door hardware and existing keys , you need a retrofit smart lock . These replace only the interior thumb-turn side of your current single-cylinder deadbolt, making them fast to install and great for renters or homeowners who love their door's current look.

Top-rated retrofit smart locks on the market include:

The gold standard for retrofit locks. It clamps directly onto your existing interior thumb-turn while leaving the outside untouched. It features built-in Wi-Fi, auto-unlock/lock via geofencing, and works with Alexa, Google, and Apple HomeKit.

A fantastic, feature-rich option that utilizes Matter-over-Thread. It installs on the inside of your existing deadbolt and comes with a wireless, waterproof keypad that supports PIN codes, fingerprints, and Apple Home Key.

Yale’s dedicated retrofit solution. It replaces just the interior thumb-turn and pairs with an optional wireless keypad (including fingerprint options), integrating smoothly with major smart home ecosystems.

Highly versatile and fits over most North American single-cylinder deadbolts. It installs in minutes with strong adhesive or a quick plate swap, and you can add an optional fingerprint/code keypad or Wi-Fi hub.

The ultimate "invisible" choice . Instead of mounting a bulky unit on the inside of your door, the Level Bolt actually replaces the internal bolt mechanism inside the door itself. Your exterior and interior trim look entirely traditional, but it gains smart capabilities via Matter/Thread.

To help narrow down the best choice for your door, let me know:

• Which smart home ecosystem do you use (Apple HomeKit, Amazon Alexa, Google Home)?
• Do you want an exterior keypad/fingerprint reader , or do you only plan to unlock via your smartphone?

If you want to keep your existing deadbolt hardware (and your current house keys), you need a retrofit smart lock . These replace only the interior thumbturn of your door, leaving the exterior appearance completely unchanged.

The top retrofit smart locks available include:

• August Wi-Fi Smart Lock (4th Gen)Go to product viewer dialog for this item. : The gold standard for retrofits. It mounts directly to the inside of your existing single-cylinder deadbolt, features built-in Wi-Fi (no separate bridge required), and lets you use your original keys from the outside. It supports Auto-Lock/Auto-Unlock and major smart home ecosystems.
• Level Bolt / Level Bolt Connect Go to product viewer dialog for this item. : If you want a completely invisible smart lock, Level Bolt replaces the internal deadbolt mechanism itself while keeping both your interior thumbturn and exterior keyway intact. From the outside and inside, the door looks 100% normal.
• Yale Approach Lock with Wi-Fi + Keypad Go to product viewer dialog for this item. : A straightforward, compact retrofit adapter from Yale that fits over most standard single-cylinder deadbolts. It is quick to install and integrates nicely with the Yale app and smart home platforms.
• SwitchBot Lock Pro Go to product viewer dialog for this item. : Highly versatile and popular for North American single-cylinder deadbolts. It installs over your existing thumbturn, offers great third-party integrations (like Matter via hub), and provides physical backup options.

To help narrow down the best choice for you, let me know:

• What smart home ecosystem do you use (Apple Home, Amazon Alexa, Google Home, or just a standalone app)?
• Do you want an external keypad added, or do you strictly plan to use your phone/key?

Yes — you want a retrofit smart lock, which keeps your existing deadbolt/keyway rather than replacing the whole lock.

Yale Approach Lock with Wi-Fi + Keypad

$179.99

SwitchBot Smart Lock Pro

$119.99

Level Bolt

$129.00

August Wi-Fi Smart Lock

$199.99

My top picks

• Yale Approach — best overall retrofit. It mounts on the inside, keeps your existing key and exterior hardware, and can add Wi-Fi and a keypad. Yale currently lists the Wi-Fi + keypad version at $179.99.
• SwitchBot Lock Pro — good if you want a relatively inexpensive retrofit that attaches over the interior side of your existing deadbolt. The current listing I found is about $120.
• Level Bolt — best if you want the lock to be virtually invisible. Its mechanism installs inside your existing deadbolt, leaving both sides looking unchanged and allowing you to keep your keys.
• August Wi-Fi Smart Lock — the classic retrofit option; it replaces the inside thumb-turn mechanism while leaving the outside/key unchanged. It's currently around $200.

One important catch: compatibility depends on the exact deadbolt. August, for example, requires a single-cylinder deadbolt, and Level has a specific compatibility list.

If you send me a photo of the inside and outside of your deadbolt, I can identify what type you have and tell you which of these will fit.