How Do Smart Locks Work? (Definitive Guide)

Smart locks are getting very popular and can be found installed throughout many homes (and businesses). The broad appeal of smart locks comes from the superb levels of comfort and smart security features they offer.

But smart locks are relatively new technology, so to speak, and a lot of people can even be scared by these automated smart locks. Truth be told, it all comes down to how smart locks work.

How do smart locks work? Smart locks are electronically operated and powered by a battery and can lock and unlock a door without a physical key. Smart locks also work with different mobile apps providing better home automation and security.

Smart locks are locks that work the same way standard mechanical locks work. That being said, smart locks are not created equal and different models can work a little differently.

So let’s take a more in-depth look.

How Do Smart Locks Work

Smart Locks vs. Traditional Locks and Deadbolts

The majority of smart locks work on the same principle a standard deadbolt works. When locked, they use a bolt to secure the door and prevent it from being open until unlocked.

In fact, often, smart locks are intended to work as a deadbolt. Some smart locks will completely replace your deadbolt, while others can be installed on top of your existing deadbolt—simply automating it and allowing you to operate the locking mechanism electronically and remotely.

Since most smart locks are designed as deadbolts, this means that they do not affect in any way the door’s lever or knob. The smart lock—or rather, smart deadbolt—is installed in addition to the lever.

Usually, the deadbolt is separated from the lever or knob. However, installing a smart lock can be problematic on doors that have the deadbolt and lever or knob as one unit.

That being said, there are also smart locks that have integrated levers instead.

Smart locks usually provide equivalent or better levels of security compared to mechanical locks. And since some smart locks are electronic, owners can benefit from using smart features that are otherwise impossible to achieve with a standard mechanical lock.

For example:

  • Smart locks can monitor the status of your door in real-time. This is often done with a magnetic proximity sensor that will detect whether or not your door is locked or left slightly ajar. If the lock is not fully engaged, some locks will sound an alarm and even send you a notification on your phone.
  • Some smart locks can also be set to lock after a set amount of time automatically.
  • Usually, smart locks allow you to set a few different user codes, which can be used by the different members of your family, guests, etc.
  • You can keep tabs on your smart locks and review detailed history logs, which is normally done through a dedicated mobile application.

Smart locks are not always keyless. Depending on how they are designed, smart locks can be opened differently using a physical key, a key card, a key fob, a key code, a wireless remote, a fingerprint, or a mobile device.


Different Types of Smart Locks and How They Work

Overall smart locks are designed to be as user-friendly as possible. And, in order to install and use a smart lock, you do not have to be particularly handy or possess any special skills.

But here’s the thing.

Not all smart locks work the same way. Upon more in-depth analysis, you will find that they can come with different features which will affect how they work.


Smart Locks With a Keypad

Keypad smart locks allow you to set a code that you can use to open your door. There are various models that offer different features. They can have either physical buttons that you can press or come with a touchscreen. Some may allow you to control them remotely, while others will not have such capabilities.

Although most smart locks that have a keypad can be set up with a few different access codes, there is also a master code that can be used to reset the smart lock in an emergency.

Can Keypad Locks Be Hacked?


Wireless Smart Locks

Wireless smart locks are the most popular choice among people. They allow you to open your door without using a physical key or entering a code.

Wireless smart locks can use several different communication protocols. They can use either Bluetooth, Wi-Fi, Zigbee, or Z-Wave technology.

The way Wi-Fi smart locks work is by directly connecting to your existing Wi-Fi network in your home. This allows the owner to control the lock and manage it remotely.

In contrast, Bluetooth locks are accessible at close range by using a Bluetooth-capable device like your smartphone, tablet, or computer.

Locks using Zigbee and Z-Wave protocols are slightly different and need a special hub capable of receiving these signals first, as these devices cannot directly communicate with your Wi-Fi network.


Proximity Smart Locks

Some smart locks are designed to open and close automatically when the owner gets near the door. However, while this can be very convenient, it can also lead to problems like accidentally unlocking the door while using the peephole.

Proximity smart locks are locked and unlocked using a wireless key fob that communicates a radio signal between the key fob and the smart lock (just like modern cars are locked and unlocked).

Some proximity locks may work using Bluetooth technology. Bluetooth works at short range (about 30 feet or so), and you can use your phone or another smart device to pair and operate your smart lock through the use of a dedicated app.


Fingerprint Smart Locks (Biometric Locks)

Some smart locks have a fingerprint scanner that can be used to unlock your door.

Fingerprint smart locks work by scanning the unique pattern of your fingers’ friction ridges. The patterns are then stored in the device’s memory.

Fingerprint scanners can work by using (1) an optical sensor, (2) a capacitive sensor, or (3) an ultrasonic sensor.

The performance of fingerprint scanners varies, but they have been proven to be extremely accurate and reliable by a comprehensive study carried out by the National Institute of Standards and Technology.

That being said, fingerprint sensors are known to have some weaknesses, and some can be cracked pretty easily depending on what technology is used.


How Are Smart Locks Powered?

Smart locks need a power source to function. They are typically powered by batteries because it is not convenient for smart locks to be hardwired due to the nature of how they are used and where they are installed.

This means that as long as the batteries in your smart lock are good and provide enough charge, your lock will work as intended. The problem here lies when the batteries run out of power. This could leave you locked outside until you replace the batteries, use a spare key, or enter through another door.

Some smart locks may have batteries on the outside, so accessing them and replacing them will be easier. (That being said, removing the batteries will not unlock the door.)

The good news is that smart locks are designed to inform you if their batteries are running low on power.


Do Smart Locks Work With Any Door?

Smart locks are designed to work with all doors that have a standard deadbolt installed on them. Smart lock levers and handles are also made to replace most standard door levers, although it is possible to have some fitment issues in certain cases.

Some chiseling or drilling may be required to ensure that the mounting plate, reinforcement plate, and strike plate align correctly.

Check out this great video covering some of these aspects.


How Smart Locks Integration Works

The majority of smart locks will come with a special dedicated mobile app that owners can use to manage and customize how their smart lock works.

The way this works is after the lock has been installed and powered on, users can download the dedicated app on their mobile phone. After they download the app, they have to pair it with the smart lock.

This process is done differently on the different devices and brands, but the manufacturers always provide detailed instructions on how to do it.

Once the smart lock has been set up, you can customize how it works using the mobile app on your phone.

Although there are many standalone smart locks, some can also be part of a larger home security system. This takes everything on a whole new level.

The electronic components allow the lock to be designed in such a way as to connect to your Wi-Fi or other electronic smart devices and smart security systems.

Many of the more popular models offer different levels of integration.

Some can be controlled through smart speakers like the ones offered by Amazon and Google.

Some smart locks can be set up to create multiple rules for complete home automation, such as adjusting your thermostat, lighting, and more upon being unlocked by a specific person.

And others can be set up to allow specific people to enter your home in a specific time window and can even integrate with Airbnb, for example.

Photo of author


Edward Clark
Edward Clark, with 15 years of hands-on experience, is a distinguished expert in smart locks and home security systems. He holds a B.S. in Computer Engineering with a focus on Cybersecurity and is a member of the Electronic Security Association (ESA). His credentials include certifications from ASIS International, IAPP, CompTIA, NTS, and CEDIA. With expertise spanning risk management, electronic security, and data privacy, he's been featured in The Guardian, Forbes, Wired, and more. Edward's mission: guiding individuals toward secure homes using the latest technologies.

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