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Your letting agent says you can’t replace the lock. The landlord says no modifications to the door. You found one you wanted, ordered it, pulled the old lock off, and discovered a non-standard backset. Wrong product.
That’s two of the most common smart lock buying mistakes, and neither is covered clearly in any buying guide.
The first is solved by a retrofit lock. The second is solved by checking your door before ordering anything.
6 smart locks tested across retrofit installs, full deadbolt replacements, and Airbnb setups.
By the end, you’ll know which type fits your door, which connectivity option won’t drain your batteries in six weeks, and which lock is right for your specific situation.
Quick Answer
The best smart locks in 2026 are the August Wi-Fi Smart Lock 4th Gen (~$230, best retrofit — replaces only the interior thumbturn, keeps your existing keys and deadbolt), the Yale Assure Lock 2 Touch (~$280, best full deadbolt replacement — fingerprint + keypad, ANSI Grade 2, DoorSense technology that detects if the door is actually closed), and the Schlage Encode Plus (~$230, best full deadbolt for Apple HomeKit and Alexa with built-in Wi-Fi and no hub). For budget, the Ultraloq U-Bolt Pro Wi-Fi (~$140) packs fingerprint, keypad, and Wi-Fi into the lowest-cost feature-complete lock on this list. For renters and Airbnb hosts, the Yale Approach + Keypad (~$150) is the most renter-friendly retrofit with keypad access.
Before ordering anything: check your door. Deadbolt replacement locks need a 2⅛-inch cross bore. Retrofit locks need a standard square thumbturn.
The full door check takes two minutes. It’s the first section below.
Check Your Door Before Buying Any Smart Lock
This is the step that causes most smart lock returns. Two minutes now saves a return shipping label later.
For deadbolt replacement locks (Schlage, Yale Assure, Ultraloq)
Full deadbolt replacement locks install into the existing bore holes in your door. Your door needs:
- Cross bore (face bore): the large hole in the face of the door where the lock body sits — needs to be 2⅛ inches (54mm) in diameter. This is standard on most US and UK residential doors built in the past 30 years. Measure across the existing hole.
- Edge bore: the small hole in the edge of the door for the latch bolt — needs to be ⅞ inch (22mm). Standard on almost all residential doors.
- Backset: the distance from the edge of the door to the centre of the cross bore. Standard US backsets are 2⅜ inches or 2¾ inches. Check which your door has — most smart deadbolts include two strike plates to accommodate both, but confirm before ordering.
For retrofit locks (August Wi-Fi 4th Gen, Yale Approach)
Retrofit locks attach to the interior side of your existing deadbolt, replacing only the thumbturn. Your existing deadbolt, cylinder, and keys remain in place. Your door needs:
- A standard deadbolt is already installed. The retrofit mounts onto the existing interior mechanism.
- A compatible thumbturn shape. Most retrofit locks work with standard single-cylinder deadbolts. Some non-standard European oval cylinder locks and double-cylinder deadbolts (keyed on both sides) are not compatible. Check whether your existing deadbolt has a standard thumbturn.
- Adequate interior door clearance. Retrofit locks add approximately 2 inches of depth to the interior. Measure the space between your door and any nearby door frame or architrave.
⚠️ For renters — check your tenancy agreement before buying any smart lock
Most UK and US tenancy agreements prohibit replacing door locks without the landlord’s permission. Retrofit locks are the renter-safe option; they attach to your existing lock hardware without modifying anything the landlord owns. When you move out, unscrew the retrofit adapter and reinstall the original thumbturn. The door is restored exactly as you found it in 10 minutes.
Full deadbolt replacement requires removing the landlord’s lock and replacing it with your own. Most landlords permit this if you restore the original hardware on departure, but ask first.
Wi-Fi vs Bluetooth vs Z-Wave: Which Connectivity Is Right for You
Every smart lock buying guide lists connectivity specs. None explains the practical consequence that matters most: battery life.
| Connectivity | Battery life (typical) | Hub needed? | Remote access? | Best for |
|---|---|---|---|---|
| Wi-Fi only | 3–6 months | No | Yes — always | Simplest setup, frequent remote access |
| Bluetooth + Wi-Fi bridge | 6–12 months | Bridge required | Yes — via bridge | Longer battery, still remote capable |
| Z-Wave + hub | 12–18 months | SmartThings or similar | Yes — via hub | Longest battery, existing hub setup |
| Matter over Thread | 6–10 months | Thread border router* | Yes — local | Future-proof, multi-ecosystem, local control |
*Thread border routers: Apple TV 4K (2nd gen+), HomePod mini, Nest Hub 2nd Gen. If you own any of these, you already have Thread infrastructure.
The battery reality for Wi-Fi locks: a Wi-Fi smart lock maintains a constant connection to your router. Every access check, every lock status poll, every remote command routes through this live connection.
Four AA batteries power this for approximately 3–6 months under normal use. If your lock is in a high-traffic area (30+ entries per day) or in a cold location (cold temperatures reduce battery capacity significantly), change batteries every 3–4 months.
Bluetooth-only locks use the radio only when a phone is nearby or when a command arrives via an accompanying Wi-Fi bridge.
Battery life doubles or triples. The trade-off: without the bridge, no remote access. With the bridge, which plugs into any USB outlet near your router, you get full remote access at a lower battery cost than Wi-Fi Direct.
Are Smart Locks as Secure as Standard Deadbolts?
This is the objection most buyers have before purchasing. The answer is more nuanced than most reviews acknowledge.
The physical security is identical to the underlying lock. A smart lock uses the same deadbolt bolt and the same physical lock cylinder (or replaces the cylinder with an equivalent).
Pick resistance, bump resistance, and kick resistance depend on the deadbolt grade, not the electronics attached to it. An ANSI Grade 1 smart lock is as physically secure as a non-smart ANSI Grade 1 deadbolt.
The electronic security depends on the brand. Low-quality smart locks have been demonstrated to accept replay attacks, capturing a Bluetooth signal and replaying it to unlock.
High-quality smart locks (Schlage, Yale, August, Nuki) use encrypted rolling codes that can’t be replayed. Every lock on this list uses encrypted communication.
The key-copying risk disappears. A standard keyed deadbolt can be compromised by anyone who borrows your key for 60 seconds, or by a key-cutting machine.
Smart locks with keypad or fingerprint access eliminate this risk. A code you share can be revoked remotely. A physical key copy cannot.
💡 What I check on every smart lock: the ANSI Grade
ANSI/BHMA security grades are the relevant benchmark for deadbolt strength. Grade 1 is the highest residential rating tested to withstand 250,000 open/close cycles, 10 door strikes at 75ft-lb, and 150lb of pull on the bolt. Grade 2 is the standard residential grade, still very strong, tested to 150,000 cycles.
Of the locks on this list, Schlage Encode Plus is Grade 1. Yale Assure Lock 2, August Wi-Fi 4th Gen (via the underlying deadbolt), and Nuki are Grade 2 equivalents. The Ultraloq is Grade 3. For a front door, Grade 1 or 2 is the appropriate choice. Grade 3 is fine for an interior door or secondary entrance.
Best Smart Locks for Airbnb Hosts and Short-Let Properties
The fastest-growing smart lock buyer segment in 2026. The specific requirements are different from a standard household, and no buying guide addresses them directly.
A short-let host needs:
- Time-limited access codes — a guest code that works from check-in to check-out and expires automatically
- Remote revocation — the ability to cancel a code remotely if a guest extends, leaves early, or you need to deny access
- Access log — a record of when the lock was used and by which code, viewable remotely
- No physical key handover — the ability to manage the entire process without being physically present
Best choice for Airbnb hosts: Schlage Encode Plus or Nuki Smart Lock Ultra.
The Schlage Encode Plus supports up to 100 unique access codes, each with scheduled access times. Set a guest code to work only from Friday, 3 pm to Sunday, 11 am. The code expires automatically. You receive a notification each time it’s used. The entire management happens in the Schlage Home app from anywhere. No hub required, built-in Wi-Fi handles everything.
The Nuki Smart Lock Ultra goes further with native Airbnb integration. Connect your Airbnb account, and Nuki automatically generates a unique access code for each booking tied to the confirmed check-in and check-out times. Guest codes appear in the Nuki app. When the booking ends, the code expires. Zero manual code management per booking.
For cleaners and maintenance staff, both locks support recurring schedules — a code that works every Tuesday between 10 am and 2 pm, automatically, without re-entering each week.
Best Smart Locks 2026 — Quick Comparison
| Lock | Best For | Price | Type | Access methods | Works with | ANSI Grade |
|---|---|---|---|---|---|---|
| August Wi-Fi Smart Lock 4th Gen | Best retrofit | ~$230 | Retrofit | App, auto-unlock, key | Alexa, Google, HomeKit | Depends on existing lock |
| Yale Assure Lock 2 Touch | Best full deadbolt | ~$280 | Full deadbolt | Fingerprint, keypad, app | Alexa, Google, HomeKit | Grade 2 |
| Schlage Encode Plus | Best HomeKit + Airbnb | ~$230 | Full deadbolt | Keypad, app, key | Alexa, Google, HomeKit | Grade 1 ✅ |
| Ultraloq U-Bolt Pro Wi-Fi | Best budget features | ~$140 | Full deadbolt | Fingerprint, keypad, app, key | Alexa, Google | Grade 3 |
| Yale Approach + Keypad | Best renter retrofit | ~$150 | Retrofit + wireless keypad | Keypad, app, key | Alexa, Google, HomeKit | Depends on existing lock |
| Nuki Smart Lock Ultra | Best Matter/Airbnb | ~$200 | Retrofit | App, auto-unlock, key | Alexa, Google, HomeKit (Matter) | Depends on existing lock |
The 6 Best Smart Locks in 2026
1. August Wi-Fi Smart Lock 4th Gen — Best Retrofit Smart Lock
Who it’s for: Renters and homeowners who want smart lock features without replacing or modifying the existing deadbolt
Price: ~$230 | Type: Retrofit — attaches to the interior of the existing deadbolt | Connectivity: Wi-Fi built-in
Access: App, auto-unlock, Alexa/Google/HomeKit voice | Battery: 4x AA (~6 months)
Works with: Alexa, Google Home, Apple HomeKit
The August Wi-Fi Smart Lock replaces only the interior thumbturn of your existing deadbolt. Your exterior keyhole stays in place. Your existing keys still work.
The deadbolt cylinder, the part the landlord or previous owner bought, remains untouched. Only the interior mechanism is new hardware.
Installation takes around 10 minutes with a screwdriver. Remove the two screws holding the interior thumbturn. Fit the August mounting plate.
Attach the August Smart Lock body. Done. The lock controls your existing bolt using a motor that drives the thumbturn mechanism.
Auto-unlock is the feature that makes retrofit smart locks genuinely different from a keypad lock.
The August uses your phone’s GPS and Bluetooth to detect when you arrive home and unlock automatically.
Your hands are full of shopping. You approach the door. It unlocks before you reach it. You push the door open without touching the lock or your phone.
The 4th Gen has built-in Wi-Fi; previous August generations needed a separate Wi-Fi bridge for remote access. Remote locking and unlocking from anywhere, access log, and guest access management all work without a hub.
The limitation renters need to know: the August doesn’t include a keypad. Access without a phone requires using a physical key. For keypad access alongside app control, add the August Smart Keypad (~$80, sold separately) or step up to the Yale Approach + Keypad bundle below, keypad included.
2. Yale Assure Lock 2 Touch — Best Full Deadbolt Smart Lock
Who it’s for: Homeowners wanting a complete smart deadbolt with fingerprint, keypad, and DoorSense door monitoring
Price: ~$280 | Type: Full deadbolt replacement | Connectivity: Wi-Fi (Matter compatible)
Access: Fingerprint, keypad, app, Apple Home | ANSI Grade: 2 | DoorSense: Yes
Works with: Alexa, Google Home, Apple HomeKit, Samsung SmartThings
The Yale Assure Lock 2 Touch is the best all-around full deadbolt smart lock available in 2026.
The fingerprint reader stores up to 25 fingerprints; each person in the household gets their own, and the access log records which fingerprint unlocked the door and when.
DoorSense is the feature that separates Yale from every other smart lock on this list. A small magnetic sensor mounts in the door frame and tells the lock whether the door is physically closed.
Most smart locks auto-lock on a timer; they lock the deadbolt whether or not the door is properly closed.
A door that’s slightly ajar deadbolts with the bolt pressing against the strike plate, damaging both over time and leaving the door technically locked but not actually closed.
With DoorSense, the Assure Lock 2 Touch only auto-locks when it has confirmed the door is fully closed and latched. It sends an alert if you lock up and the door is still ajar.
Over a year of use in a house with a warped door frame, DoorSense prevented multiple instances of locking an open door.
Matter support means QR code setup in Google Home, Alexa, or Apple HomeKit, no skill linking, and no cloud account required for platform integration. The lock communicates locally through the Thread border router built into your Apple TV or Nest Hub.
The door check is important for this model: it requires a standard 2⅛-inch cross bore and ⅞-inch edge bore. Installation takes approximately 30 minutes. A screwdriver is all the tools needed.
The keypad exterior is compact — narrower than most smart lock keypads, which blends better with standard door hardware aesthetically.
3. Schlage Encode Plus — Best Smart Lock for HomeKit and Airbnb Hosts
Who it’s for: Apple HomeKit households and Airbnb hosts needing 100 unique access codes with scheduled time windows
Price: ~$230 | Type: Full deadbolt replacement | Connectivity: Wi-Fi built-in, no hub
Access: Keypad (100 codes), app, key, HomeKit | ANSI Grade: 1 (highest residential rating)
Works with: Alexa, Google Home, Apple HomeKit
The Schlage Encode Plus is the only ANSI Grade 1 smart lock on this list. Grade 1 locks withstand 250,000 cycles, 10 door strikes at 75ft-lb, and 150lb of pull on the bolt.
This is the standard specified for commercial and high-security residential applications. If physical security is the primary concern, the Schlage is the correct choice.
The 100-code capacity with scheduled access windows is what makes the Encode Plus the right lock for Airbnb hosts and short-let properties.
Each guest gets a unique code tied to their check-in and check-out time, active only during their stay, expired automatically.
The Schlage Home app shows an access log of every code use: which code, what time, locked or unlocked. Cleaners get recurring codes (Tuesday 10 am–2 pm, every week).
No physical key management is needed at any point.
Apple HomeKit support is native and direct. Scan the HomeKit setup code on the lock body, and it joins the Apple Home app immediately.
Siri commands work: “Hey Siri, is the front door locked?” and “Hey Siri, lock the front door” both respond without needing a hub or bridge.
No fingerprint reader. The Encode Plus uses a backlit keypad only, no biometric option. For Yale’s fingerprint capability at a higher price, see Pick 2.
For the Schlage Grade 1 security without a fingerprint requirement, this is the correct trade-off.
4. Ultraloq U-Bolt Pro Wi-Fi — Best Budget Smart Lock
Who it’s for: Budget buyers who want fingerprint, keypad, and Wi-Fi in a single sub-$150 lock
Price: ~$140 | Type: Full deadbolt replacement | Connectivity: Wi-Fi built-in
Access: Fingerprint, keypad, app, key, fob, NFC | ANSI Grade: 3
Works with: Alexa, Google Home
The Ultraloq U-Bolt Pro Wi-Fi offers six access methods for $140: fingerprint, keypad code, app, physical key, Bluetooth fob, and NFC card.
No other smart lock at this price offers this range. For a secondary entrance, a back door, a garage entry, or a granny flat, the Ultraloq delivers full smart functionality at the lowest cost on this list.
Fingerprint unlock responds in under half a second on a freshly enrolled print. The sensor stores up to 100 fingerprints, every household member, plus guests get their own.
The keypad is anti-peep, meaning the capacitive touchscreen requires deliberate touch rather than a light brush, reducing accidental activations in rain or wind.
The U-Bolt Pro has the strongest Wi-Fi range of any lock tested, maintaining connection through walls and at distances where other Wi-Fi locks drop.
For doors at the back of a property, further from the router, this range advantage is meaningful.
The honest limitation: ANSI Grade 3. The physical security rating is the weakest on this list. For a front door on a busy street, Grade 1 or 2 is the appropriate standard, see Schlage or Yale.
The Ultraloq is the right pick for secondary entrances, interior doors, and budget-priority situations where the risk profile allows a Grade 3 lock.
5. Yale Approach + Keypad — Best Retrofit Smart Lock for Renters
Who it’s for: Renters who want keypad access alongside app control, without modifying the existing deadbolt
Price: ~$150 (lock + wireless keypad bundle) | Type: Retrofit + wireless keypad
Connectivity: Wi-Fi built-in | Access: Keypad, app, auto-unlock, key
Works with: Alexa, Google Home, Apple HomeKit
The Yale Approach solves the problem that August Wi-Fi doesn’t: renter-friendly retrofit with keypad access included.
The Yale Approach attaches to the interior of your existing deadbolt exactly like the August, 10 minutes, one screwdriver, no modification to landlord hardware.
The wireless Yale Keypad mounts on the exterior frame with adhesive or two small screws. No wiring. No deadbolt cylinder integration.
The wireless keypad communicates with the Yale Approach via Bluetooth. Enter your code on the keypad, the Approach receives the signal and drives the deadbolt.
No key handover. No phone required. Guests, family, and workmen each get their own code, revocable remotely from the Yale Access app.
For renters, the move-out process is the cleanest of any smart lock system. Remove the Yale Approach from the interior thumbturn (two screws).
Remove the keypad from the door frame (peel off the adhesive pad or fill two small screw holes). Reinstall the original thumbturn. Done.
The door is restored in under 15 minutes with no trace of the smart lock system.
The Yale Approach + Keypad works with August smart locks, too. The Yale Keypad also works with August locks already installed, designed for the 750,000+ August units already in US homes. One keypad, multiple lock compatibility.
6. Nuki Smart Lock Ultra — Best Smart Lock for Matter and Airbnb Integration
Who it’s for: Airbnb hosts wanting automated guest code generation, and multi-ecosystem homes needing Matter over Thread
Price: ~$200 (lock only) | Type: Retrofit | Connectivity: Wi-Fi + Matter over Thread
Access: App, auto-unlock, key, optional keypad (sold separately) | Battery: Built-in USB-C rechargeable (~6 months)
Works with: Alexa, Google Home, Apple HomeKit (Matter)
The Nuki Smart Lock Ultra is the only smart lock on this list with native Airbnb integration.
Connect your Airbnb account, and every confirmed booking automatically generates a unique time-restricted code matching check-in and check-out times.
When the booking ends, the code expires. No manual code creation per booking, no risk of forgetting to revoke a code, no physical key handover at any point.
For hosts managing multiple properties or back-to-back bookings, this automation eliminates the most time-consuming part of short-let management.
The access log records every code use with a timestamp, giving a clear record of when the property was accessed and by whom.
Matter over Thread is the other standout feature. The Nuki connects through the Thread border router built into an Apple TV 4K, HomePod mini, or Nest Hub 2nd Gen.
Commands route locally, no Nuki cloud in the chain for standard lock and unlock operations. This means the lock works during internet outages, responds faster than cloud-routed Wi-Fi locks, and isn’t affected by Nuki’s servers having downtime.
US compatibility note: the Nuki Smart Lock Ultra US version is a retrofit that fits standard US single-cylinder deadbolts with a standard square thumbturn.
It doesn’t fit all European-style oval cylinder locks or non-standard thumbturn shapes. Verify your existing deadbolt is a standard US single-cylinder before ordering.
The European version supports oval cylinders common in German and Austrian door hardware.
Frequently Asked Questions About Smart Locks
Are smart locks safe and secure?
Smart locks are as physically secure as the underlying deadbolt; the bolt mechanism, pick resistance, and bump resistance all depend on the deadbolt grade, not the electronics.
High-quality smart locks (Schlage, Yale, August, Nuki) use encrypted rolling codes that prevent replay attacks.
ANSI Grade 1 smart locks are rated for the same physical attack resistance as non-smart Grade 1 deadbolts.
Additionally, smart locks eliminate the key-copying risk of standard locks; a code can be revoked remotely, a physical copy of your key cannot.
Can smart locks be hacked?
Low-quality smart locks have demonstrated Bluetooth replay vulnerabilities, capturing and replaying an unlock signal.
Every lock on this list uses encrypted rolling codes that change with each use, preventing replay.
The more realistic security risk is guessable PIN codes; use codes that aren’t birthdays, house numbers, or sequential numbers.
Enable lockout mode after failed attempts (supported by all locks on this list) to prevent brute-force keypad attacks.
Do smart locks work without Wi-Fi?
Physical keypad codes and fingerprint access (where available) work without any internet connection; the lock processes these locally.
App-based remote locking and unlocking require an active internet connection. Auto-unlock (phone proximity detection) requires both Bluetooth and the internet.
During an internet outage, you can still use the lock via keypad code or physical key; you simply lose remote access and smart home automation until connectivity is restored.
What happens when a smart lock battery dies?
All locks here use standard AA batteries or a rechargeable internal battery.
They provide low-battery warnings, typically 4–8 weeks before failure, via the app.
If the battery dies completely, most smart locks have a physical key backup.
Both also accept a 9V battery pressed against the exterior contacts, and one emergency unlock when the internal batteries are dead.
Always carry a physical key as backup.
Can I install a smart lock myself?
Yes, all smart locks on this list are designed for DIY installation with a screwdriver. Retrofit locks (August, Yale Approach, Nuki) take approximately 10 minutes, no door modification required.
Full deadbolt replacements (Schlage, Yale Assure, Ultraloq) take 20–30 minutes and involve removing the existing deadbolt and installing the new one in the same bore holes.
If your door has non-standard bore dimensions or a non-standard backset, additional work may be needed, check your door measurements against the product specs before ordering.
Final Verdict — Which Smart Lock Should You Buy?
✅ You rent and can’t replace the deadbolt — want app control and auto-unlock
Buy: August Wi-Fi Smart Lock 4th Gen.
Attaches to the interior thumbturn in 10 minutes. Existing keys work. Auto-unlock detects your arrival and unlocks before you reach the door. Built-in Wi-Fi, no bridge needed. Move out, unscrew, and reinstall the original thumbturn. Leave no trace.
✅ You rent and want keypad access in addition to app — renter-safe setup
Buy: Yale Approach + Keypad bundle.
$150 including keypad. Retrofit installs without modifying the existing deadbolt. Wireless keypad attaches to the exterior frame with adhesive, no wiring. Code-based access for family and guests, revocable remotely. Cleanest move-out of any smart lock system, fully reversible in 15 minutes.
✅ You own your home and want the highest security rating with HomeKit
ANSI Grade 1, the highest residential security rating. 100 scheduled access codes. No hub required. Native HomeKit support. The only Grade 1 smart lock on this list. For a front door on any property where security is the priority, this is the correct pick.
✅ You want fingerprint access, DoorSense monitoring, and Matter support
Buy: Yale Assure Lock 2 Touch.
25 fingerprints. DoorSense confirms the door is actually closed before auto-locking. Compact keypad design. Matter via Thread for local processing and multi-ecosystem support. The most complete full-deadbolt smart lock in 2026.
✅ You host on Airbnb and want automated guest code generation
Native Airbnb integration, guest codes generate automatically from confirmed booking times and expire at checkout. Matter over Thread for local processing. Retrofit keeps your existing keys. The only lock on this list that eliminates manual code management for short-let properties.
