By James Walker | Home Automation & Security
ā” Quick Answer:
Before buying a smart lock, check your door’s compatibility (bore hole size, backset, thickness), decide on connectivity (Wi-Fi, Z-Wave, Zigbee, or Bluetooth), confirm your smart home ecosystem, plan for backup entry, and review the brand’s privacy policy. Renters should also verify lease terms before making any changes.
Smart locks are one of the most practical smart home upgrades available ā but they’re also one of the easiest to buy incorrectly. Door dimensions, wireless protocols, ecosystem compatibility, battery life, and privacy policies all affect whether your new smart lock will work smoothly or cause daily headaches. This guide covers everything you should evaluate before you click buy, so you end up with a lock that genuinely fits your door, your home, and your habits.
Lock Types
Connectivity & Protocols
Privacy & Security
Buying Mistakes to Avoid
ā ļø Safety & Educational Disclaimer
This article is for general educational and purchasing guidance only. It does not guarantee security outcomes or replace advice from a licensed installer, electrician, or security professional. Some installations may require licensed electrical work or local permit compliance. Always check your local building codes and consult a qualified professional when needed.
Why Knowing What to Ask Before You Buy Matters More Than the Brand
Most people shopping for a smart lock start by searching for “best smart lock” and end up on a list of popular models. What that approach misses is the step that actually determines whether any lock will work well for you: understanding your specific door, your connectivity setup, and your household’s daily habits.
Knowing what you should know before buying a smart lock means fewer returns, fewer compatibility headaches, and a much smoother installation day. The questions you ask before buying are more important than the star rating of any particular product. This guide is structured to walk you through each of those questions in order ā from physical door measurements all the way to privacy policy reviews.
Step 1 ā Check Your Door Before You Buy Anything
The single biggest cause of smart lock returns is a mismatch between the lock and the door. Before you evaluate any product, spend five minutes measuring your door. Three numbers matter most.
Bore Hole Diameter
The bore hole is the circular hole through which the lock body passes. Standard US doors have a 2-1/8″ bore hole. Most smart locks are designed for this size. If your door has a smaller or older bore hole, you may need a locksmith to resize it before a modern smart lock will fit ā this is not a DIY drill task for most homeowners.
Backset Distance
Backset is the distance from the center of the bore hole to the edge of the door. US doors typically use either 2-3/8″ or 2-3/4″ backset. Most smart locks include an adjustable latch bolt that covers both. Measure yours before buying ā the product packaging will list which backsets are supported.
Door Thickness
Standard US doors are 1-3/8″ to 1-3/4″ thick. Thicker doors (common in older homes or commercial-style entries) may not fit within the mounting reach of a standard smart lock. Check the product specs for the maximum supported door thickness and measure yours before ordering.
š Note
Also check whether your door currently has a deadbolt. Most smart locks designed for front doors expect a standard deadbolt prep. If your door only has a knob latch and no deadbolt bore hole, you’ll need a locksmith to drill the bore hole before installing any deadbolt-style smart lock. Full-replacement smart deadbolts replace the entire deadbolt assembly; retrofit adapters work only if a deadbolt is already installed.
Before evaluating any product listing, walk through this pre-purchase compatibility check to confirm your door can accept the lock type you’re considering.
š Pre-Purchase Door Compatibility Check
Yes ā most smart locks will fit. No ā hire a locksmith to resize before buying.
Both are common. Confirm the lock you’re buying supports your measurement.
Standard range. Thicker doors may need an extended mounting plate ā check specs.
Yes ā retrofit adapters and full-replacement deadbolts both work. No ā full-replacement only (locksmith may be needed).
Exterior hardware changes may require landlord written permission. Retrofit adapters may be a safer option.
Complete all five checks before evaluating any specific product. This saves time and avoids expensive returns.
Step 2 ā Understand the Three Smart Lock Formats
Not all smart locks work the same way. Once you know your door is compatible with a lock type, you need to choose which format fits your situation.
š Full-Replacement Smart Deadbolt
Replaces your existing deadbolt entirely ā exterior keypad or reader plus interior motor assembly. Includes a motorized bolt and usually a backup physical key slot. Best for homeowners who want a clean, all-in-one smart lock. Requires standard door prep and is typically straightforward to install with a screwdriver.
š Retrofit / Adapter Lock
Attaches to your existing deadbolt’s interior thumb turn without touching exterior hardware. Your existing key and keyhole remain unchanged. Popular with renters and users who want smart access without altering the door’s exterior appearance. Requires a compatible existing deadbolt ā check the brand’s compatibility list before buying.
šŖ Smart Lever / Knob Lock
Replaces a lever handle or knob ā common in interior doors, secondary entries, or some commercial-style front doors. These do not include a deadbolt. For front door use, a dedicated smart deadbolt is generally recommended alongside a lever lock if you go this route.
š Which Format Is Right for You?
Own your home and want keypad access ā full-replacement deadbolt. Rent and need interior-only ā retrofit adapter. Secondary door or interior use ā smart lever. Need to support multiple ecosystems ā check Matter compatibility across all three format types before deciding.
Smart Lock Format Comparison
Step 3 ā Choose the Right Connectivity Protocol for Your Home
Connectivity is one of the most confusing parts of buying a smart lock ā and one of the most important. The protocol determines whether you need a hub, how reliable remote access is, and how well the lock integrates with your existing smart home setup.
Wi-Fi Direct Locks
Wi-Fi locks connect directly to your home network ā no hub required. They’re the easiest to set up and offer full remote access out of the box. The trade-off is higher battery drain than hub-based protocols, and they depend on your router’s Wi-Fi signal reaching the front door reliably. If your front door is far from the router, a Wi-Fi dead zone can make the lock unreliable for remote access.
Z-Wave and Zigbee Locks
Z-Wave and Zigbee locks communicate with a hub (such as SmartThings, Hubitat, or Amazon Echo with Zigbee built in) rather than connecting directly to Wi-Fi. They use significantly less power than Wi-Fi, which means better battery life. They also benefit from mesh networking ā other Z-Wave or Zigbee devices in the home extend the signal range. If you already have a compatible hub, these are often the most reliable long-term choice.
Bluetooth Locks
Bluetooth-only locks work when your phone is physically close to the door. They typically have the best battery life of all protocols. The limitation is that they don’t provide remote access unless you add a bridge device that connects the lock to your Wi-Fi network. Good for users who primarily want proximity auto-unlock and don’t need to check lock status from across town.
Matter / Thread Locks
Matter is a newer smart home standard designed to make devices work across Apple HomeKit, Amazon Alexa, Google Home, and SmartThings without ecosystem lock-in. Thread is the wireless protocol Matter uses for battery-powered devices. Matter/Thread smart locks are a good future-proof choice if you use multiple smart home platforms or plan to switch ecosystems. The product selection is growing but remains smaller than Wi-Fi or Z-Wave options as of 2025.
Connectivity Protocol Quick Reference
Step 4 ā Match the Lock to Your Smart Home Ecosystem
One of the most overlooked questions when people think about what they should know before buying a smart lock is ecosystem compatibility. A smart lock that doesn’t work natively with your existing smart home devices will require workarounds, third-party bridges, or manual control ā defeating part of the purpose.
š” Tip
Before buying, check the product listing for the exact voice assistant and hub compatibility it supports. “Works with Alexa” can mean different things ā some locks only support voice commands to lock/unlock, while others support full automation routines. “Works with Apple HomeKit” is a more specific certification. Look at the brand’s own compatibility documentation, not just the product title, to understand what level of integration is actually available.
If you use Amazon Alexa, look for locks with native Alexa support or a Zigbee connection to an Amazon Echo hub. If you’re in the Apple ecosystem, look for HomeKit-certified locks ā these support the Home app natively and can trigger HomeKit automations. Google Home users should verify that the lock’s app supports Google Home Assistant routines. SmartThings and Hubitat users typically have the widest compatibility through Z-Wave and Zigbee support.
Use this decision path to match your current ecosystem to the right smart lock protocol before you start comparing products.
š Ecosystem ā Protocol Match Guide
š Apple HomeKit
Look for HomeKit-certified locks. Yale Assure Lock 2 (HomeKit) is a common example. Matter/Thread locks also work with HomeKit. Avoid non-certified locks claiming HomeKit support ā they may lose functionality after firmware updates.
š Amazon Alexa
Wi-Fi locks with direct Alexa support or Zigbee locks paired to an Echo hub. Z-Wave locks work via SmartThings linked to Alexa. Verify that your Echo device has a Zigbee hub built in before relying on it.
š Google Home
Wi-Fi locks with Google Home integration or Matter-compatible locks. Check the lock’s app description for “Works with Google Home” compatibility and verify it supports routines, not just voice commands.
āļø SmartThings / Hubitat
Z-Wave and Zigbee locks offer the most robust integration with SmartThings and Hubitat. These platforms support the widest range of automation rules and local processing, which can reduce cloud dependency.
Always verify compatibility on the manufacturer’s official product page, not only the Amazon listing ā compatibility details are more accurate and up to date there.
Step 5 ā Understand Battery Life and Backup Entry Options
Battery failure is the most common reason people get locked out of a smart lock. Before buying, confirm that the lock you’re considering has reliable low-battery alerts and at least one backup entry option.
Low-battery alerts: Most smart locks send push notifications through their app when the battery drops to a certain level ā usually 20ā30%. Confirm this feature is available before buying, and plan to change batteries proactively rather than waiting for the lock to stop working.
Emergency power port: Some models include a 9V battery terminal on the exterior that allows temporary power to unlock the door even when the main batteries are dead. This is an especially useful feature for households where battery replacements might be forgotten.
Physical key backup: The majority of full-replacement smart deadbolts include a physical key slot on the exterior. Retrofit adapters typically don’t add a key slot ā they rely on the existing exterior key that was already there. Confirm which backup methods are available for any model you’re evaluating.
ā ļø Warning
Never purchase a smart lock that has no physical backup entry method unless you’ve explicitly planned for an alternative ā such as a lockbox with a spare key kept at a neighbor’s home. Relying exclusively on an app or keypad code without any backup is a significant lockout risk, especially during power outages, internet disruptions, or app server issues. Always configure at least two different ways to unlock the door before you depend on the smart lock daily.
Safe Setup Choices vs. Common Risky Shortcuts
Step 6 ā Review Privacy and Data Practices Before You Commit
A smart lock collects data about when your door is locked and unlocked, who triggered each event, and from where. Before buying any smart lock, reviewing the brand’s data practices is one of the most important ā and most commonly skipped ā steps in the buying process.
The FTC provides guidance on connected device privacy rights for consumers at consumer.ftc.gov. CISA offers smart home cybersecurity guidance at cisa.gov. Reviewing both before purchasing can help you understand what questions to ask about any connected device you bring into your home.
Key Privacy Questions to Ask About Any Smart Lock
āļø Cloud Required?
Does the lock work without an active cloud account? Some locks become non-functional if the manufacturer shuts down cloud services. Look for locks that support local operation or have a strong track record of maintaining their cloud infrastructure.
š Access Log Storage
Who can see your entry/exit logs? Are they stored locally on the device, in the cloud, or both? Can they be deleted? Confirm these details in the app settings before choosing a lock if access log privacy matters to your household.
š Third-Party Data Sharing
Does the brand share usage data with advertising partners? This is disclosed in the privacy policy, not the product listing. Reading at least the summary section of the privacy policy before buying is worth the five minutes it takes.
š”ļø Firmware Updates
Does the brand push regular firmware updates? An unpatched smart lock may be exposed to known vulnerabilities. Check the brand’s support page or app store reviews for update frequency before committing to any product.
Here is a simple privacy evaluation path to run through before finalizing your smart lock purchase.
š Smart Lock Privacy Evaluation Path
Yes ā check if local backup mode exists. No cloud at all ā good for privacy.
Yes ā decide if you’re comfortable with that before purchasing.
More than 12 months ago ā research the brand’s support track record further before buying.
Yes ā enable it immediately after setup. No ā use a very strong, unique password and consider a different brand.
This path is a practical starting guide, not a comprehensive security audit. Privacy practices can change ā reviewing the brand’s privacy policy periodically after purchase is also worthwhile.
Step 7 ā Decide Which Access Methods You Actually Need
Smart locks offer a range of ways to unlock: keypad code, smartphone app, fingerprint, key fob, voice assistant, or auto-unlock via Bluetooth proximity. Before buying, think through which of these your household will actually use every day ā not which ones sound impressive in a product listing.
Keypad / touchscreen: The most universally useful access method. Doesn’t require a phone, works for kids and guests, and doesn’t depend on Bluetooth or Wi-Fi being operational at the moment. If you buy nothing else, a keypad is the one feature worth prioritizing.
Smartphone app: Useful for remote monitoring, access logs, and granting temporary codes to guests. Less useful as your primary daily unlock method ā dead phone batteries, slow Bluetooth handshake, or spotty Wi-Fi can introduce friction.
Fingerprint: Fast and convenient for regular household members. Worth considering if you have children who struggle to remember codes or if you frequently carry groceries or packages. Not all fingerprint sensors perform equally well in cold or wet conditions ā read user reviews for outdoor performance before buying.
Voice assistant: Convenient for confirming lock status or locking the door from across the house. Most platforms require an extra confirmation step to unlock via voice (a PIN spoken aloud) for security reasons.
Smart Lock Fit by Household Type and Situation
Common Buying Mistakes and How to Avoid Them
In my experience testing and setting up smart locks across different door types and home configurations, certain mistakes come up repeatedly ā especially with first-time buyers. Here’s what to watch for.
Buying Mistakes vs. Better Choices
What Experienced Smart Home Users Check That Beginners Often Skip
Beyond the basics, there are a handful of things that separate a well-thought-out smart lock setup from one that creates headaches within the first few weeks.
Check the ANSI/BHMA grade. This rating measures the physical durability and cycle life of the deadbolt mechanism. Grade 1 is the highest residential rating, Grade 2 is standard residential, and Grade 3 is light-duty. Many smart locks are Grade 2. Some brands offer Grade 1 options. Grade is listed in the product spec sheet, not usually in the main product description.
Read app store reviews, not just product reviews. App quality significantly affects day-to-day smart lock usability. A lock with strong hardware but a poorly maintained app leads to frustration. Filter app store reviews by the most recent ratings to see whether the experience has improved or declined with recent updates.
Plan for auto-lock from day one. Auto-lock ā which triggers the bolt automatically after a set delay when the door is closed ā is one of the most practically useful features of any smart lock. Enable it immediately during setup rather than as an afterthought. Most smart lock users who don’t use auto-lock report that they still occasionally forget to lock manually, which defeats part of the purpose of upgrading.
Use time-limited guest codes for visitors. If your smart lock supports scheduled or expiring access codes, always use them for housekeepers, dog walkers, contractors, and guests instead of sharing your permanent code. Time-limited codes automatically expire after the scheduled window, so you don’t need to remember to remove access afterward.
Before finalizing any smart lock purchase, check this list of red flags that suggest a product or setup may have issues worth investigating further.
š© Smart Lock Purchase Red-Flag Checklist
One or two yellow flags don’t automatically disqualify a product, but they’re worth researching further before purchasing.
Not every evaluation step carries equal weight. Here’s a relative priority guide to help you focus your research time where it matters most.
š Pre-Purchase Evaluation Priority Guide
A practical priority guide ā not scientific rankings. Adjust based on your situation.
These bars represent a practical evaluation guide based on common smart lock buying issues ā not a standardized security rating system.
š§ When to Contact a Professional
- Your door’s bore hole needs enlarging to fit a standard smart lock cylinder ā hire a locksmith rather than attempting this with a consumer drill.
- Your door is non-standard (unusually thick, commercial-grade, or made from a material other than standard wood or fiberglass) ā a locksmith can assess whether a smart lock will work with that door.
- You need multiple units rekeyed or installed across a rental property ā a licensed locksmith can coordinate bulk installation more efficiently.
- Your door frame is cracked, warped, or the door doesn’t sit level in the frame ā address the frame issue before installing any lock, smart or otherwise.
- You want to install a smart lock on a door governed by an HOA, condo association, or commercial building code ā check the requirements with your property manager or association before purchasing.
Affiliate Disclosure: This article may contain affiliate links. If you buy through these links, we may earn a small commission at no extra cost to you. We only mention products that are relevant to the topic and do not replace advice from a qualified installer or professional.
Schlage Encode Plus Smart WiFi Deadbolt
A full-replacement Wi-Fi deadbolt that connects directly to your home network without a hub. Includes a keypad, Apple HomeKit support (via Home Key), and a backup physical key slot. May support consistent daily locking routines through auto-lock scheduling. Verify current HomeKit compatibility and door spec fit on the product page before purchasing.
Yale Assure Lock 2 (Wi-Fi + Bluetooth)
A full-replacement smart deadbolt available in multiple connectivity versions including Wi-Fi, Z-Wave, and Zigbee ā making it one of the more flexible options for matching to your existing ecosystem. Includes a touchscreen keypad and backup key slot. May work with Amazon Alexa, Google Home, and Apple HomeKit depending on the version selected. Confirm which version matches your hub or ecosystem before ordering.
August Wi-Fi Smart Lock (4th Gen)
A retrofit adapter that attaches to your existing deadbolt’s interior thumb turn, leaving exterior hardware completely unchanged. Well-suited for renters and users who want smart access without modifying their door’s appearance. May support auto-lock, access logs, and temporary guest codes through the August app. Verify that your current deadbolt model is on August’s compatibility list before purchasing.
š”ļø Safety Note
No smart lock ā regardless of price or features ā can guarantee prevention of unauthorized door access. Physical door security also depends on door frame strength, hinge quality, strike plate anchoring, and the door material itself. A smart lock installed on a weak door frame with short strike plate screws may provide less overall door resistance than a properly anchored traditional deadbolt. Always evaluate the full door system, not just the lock, when thinking about access control for your home.
Frequently Asked Questions
What should you know before buying a smart lock for a rental apartment?
Before buying a smart lock for a rental, check your lease agreement for any restrictions on changing exterior hardware. If exterior changes aren’t permitted, a retrofit adapter (which attaches to the interior thumb turn without altering the exterior) is the safest option. If you want a full-replacement deadbolt, get written landlord permission first. Always plan to restore the original hardware when you move out.
Do I need a hub to use a smart lock?
Not always. Wi-Fi and Bluetooth smart locks connect directly to your phone or home network without a hub. Z-Wave and Zigbee locks require a compatible hub (such as SmartThings, Hubitat, or an Amazon Echo with built-in Zigbee). Matter/Thread locks require a Thread border router. If you don’t want to invest in a hub, a Wi-Fi lock is the simplest path to remote access.
What happens if the smart lock battery dies?
Most smart locks send low-battery alerts well before the battery fully depletes. If the battery does die completely, most full-replacement smart deadbolts include a physical key slot as a backup. Some models also have an exterior 9V battery terminal for emergency power. Always configure and test your backup entry method before relying on the lock daily.
How do I know if a smart lock will fit my door?
Measure three things: bore hole diameter (should be 2-1/8″ for most locks), backset (distance from door edge to bore center ā typically 2-3/8″ or 2-3/4″), and door thickness (1-3/8″ to 1-3/4″ is standard). Compare these numbers against the product’s specifications before buying. If your bore hole is smaller or your door is unusually thick, consult a locksmith before purchasing.
Are smart locks private? Who can see my lock activity?
Privacy varies by brand. Most smart locks store access logs either locally on the device or in the cloud ā sometimes both. Who can view those logs and how long they’re retained depends on the brand’s privacy policy. Some brands share usage data with third parties. Before buying, review the privacy policy on the manufacturer’s website to understand how your access data is handled and whether it can be deleted.
Can I install a smart lock myself, or do I need a locksmith?
Most full-replacement smart deadbolts are designed for DIY installation using only a screwdriver, provided your door already has the correct bore hole and backset. If your door needs a new bore hole drilled, the existing hardware is non-standard, or the door frame is damaged, hiring a locksmith is the safer choice. Always test the lock with the door open before closing it and relying on the lock.
Which smart lock protocol is best for battery life?
Bluetooth-only locks typically have the longest battery life (often 12 months or more) since they use very little power. Z-Wave and Zigbee locks also offer good battery life (6ā12 months) because they use low-power mesh protocols. Wi-Fi locks drain batteries faster (typically 3ā6 months) because the Wi-Fi radio requires more power to operate. If battery replacement frequency is a concern, a Z-Wave or Zigbee lock with a compatible hub is often the best balance of battery life and remote access.
Final Thoughts
Understanding what you should know before buying a smart lock comes down to asking the right questions before you compare products: Does it fit my door? Does it match my ecosystem? What happens if the battery dies? Who can see my access data? Answering these questions first makes the product selection step much simpler ā and significantly reduces the chance of a return.
Start by measuring your door and confirming your ecosystem, then use those constraints to narrow your options. No smart lock eliminates all entry risk, but a well-chosen, properly installed smart lock with auto-lock enabled and a confirmed backup entry method can meaningfully improve daily convenience and consistent locking habits.
For non-standard doors, commercial hardware, or installations requiring bore hole enlargement, consult a licensed locksmith. If your property is governed by an HOA, condo association, or local building code, review those requirements before making any permanent door hardware change.