How Do Smart Door Locks Work?

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I’ve recently been considering whether to install a smart lock in my own home, so I did some research into how smart door locks actually work and how secure they are compared with a traditional lock.

Smart door locks work by allowing you to open and retract the deadbolt locking mechanism remotely using a smartphone app or a numeric keypad. They replace the need for a physical key and are considered to be more secure than a traditional lock.

While researching smart door locks, not only did I find out how they work, but also how they are powered, the pros and cons of Wi-Fi locks compared with those that don’t require Wi-Fi, and how secure they really are given they will usually be connected to the Internet.

What Are Smart Door Locks?

Smart door locks are electromechanical locks that allow you to open a door without the need for a physical key. They can be controlled remotely using an app on your smartphone or have a numeric keypad on the front.

Usually, they will connect to your Wi-Fi network to receive either a code or command to lock and unlock the deadbolt using the Internet, but there are those that don’t require Wi-Fi and use Bluetooth instead.

Some will replace the existing locking system completely, whereas others will fit on top of the existing mechanism and perhaps require a few minor modifications.

Smart door locks will integrate well with the other smart devices around your home such as a video doorbell or a speaker system and can easily be controlled through a simple voice command.

You will find that a smart home hub will be needed to allow all the different devices to work with each other, so this is something to keep in mind when choosing a smart door lock.

How Are Smart Door Locks Powered?

Most smart door locks are battery powered rather than being hardwired into your mains electricity supply.

The batteries are used to power the wireless chips and LED lights that make up the lock, but more importantly power the motor inside that is responsible for locking and unlocking the door.

When you trigger the door to lock or unlock, the motor is activated and draws a significant amount of power from the batteries, much more than any of the other components that need power.

This is down to the deadbolt requiring lots of power in order to extend and retract given how heavy it is.

It is recommended that you don’t cheap out on batteries for your smart door lock otherwise you can find yourself having to replace them quite often.

Unfortunately, it’s not a case of being able to recommend a particular brand of batteries; it will take a bit of trial and error to find those that work the best and last the longest.

Ultimately, it depends on how often the door is being locked and unlocked as to which batteries you should get.

If you have the door being locked and unlocked many times throughout the day, you probably want to get a decent set of batteries and have some kept aside as a backup, but if you don’t use the door very often, a cheaper brand of battery may suffice.

smart door lock

Do Smart Door Locks Need Wi-Fi?

Some smart door locks will need Wi-Fi to function, whereas others don’t and use Bluetooth instead. There are pros and cons to both.


Smart door locks that don’t use Wi-Fi can be considered more secure than those that do.

They don’t require access to the Internet and are therefore less susceptible to hacking.

Although the chances of someone targeting your home network specifically are slim, there is always a chance that your door could be disabled remotely if it is accessible over the Internet.


Non-Wi-Fi smart door locks can end up being more reliable than their Wi-Fi-reliant counterparts as those that require Wi-Fi ultimately depend on a stable Internet connection to function.

This is why locks that don’t need Wi-Fi are recommended for those that receive an unreliable Internet connection in their home, be it an incredibly slow connection or one that drops completely on a regular basis.

The last thing you want is to be locked out of your home with no way of entering just because your door lock can’t access the Internet.

If you do go down the route of using a Wi-Fi lock, try and position your router as close to the front door as you reasonably can so it receives the best possible signal.


Wi-Fi locks generally will cost more as they often require a hub, as is the case with a lot of smart gear.

Non-Wi-Fi locks are more affordable as they don’t require any additional costs to function. Installing the lock itself is all that is needed.


You tend to get more functionality out of Wi-Fi smart door locks such as the ability to monitor people entering and leaving your home remotely and being able to let guests in when you yourself are not at home.

Non-Wi-Fi locks can perform similar functions, but more is required to get them all set up. They are certainly not as easy and convenient to get setup and start making the full use out of.


Given that they usually require access to a hub, Wi-Fi smart door locks will naturally integrate better with the other smart devices around your home.

The hub acts as a central controller for all of your smart devices, regardless of the type of device and what brand it is.

The Wi-Fi locks are also much easier to control through your voice using a voice assistant such as Alexa or Google Home.

Again, some non-Wi-Fi locks can achieve similar functionality, but it certainly isn’t as streamlined and easy to setup.

Are Smart Door Locks Secure?

Smart door locks are considered more secure than a traditional lock and key in the sense that you don’t need to leave spare keys lying around.

Some of the best locks with the most functionality allow you to set the door to lock automatically after a set amount of time being unlocked, or even when you and your smartphone have left home through what is known as geo-fencing.

Those that completely replace the existing locking mechanism will also remove the keyway, so there is nothing physically available to try and pick.

Some people may argue that smart door locks aren’t secure in that they are often connected to your Wi-Fi network and can, therefore, be hacked.

This is true, but there are a few ways in which you can protect your network and hugely improve the security that your smart lock sits behind.

The first is to make sure that the app that controls your lock is always kept up to date. Manufacturers will regularly release updates for their apps, and for a good reason.

Although they may not provide additional functionality, these updates will often address security flaws and so should be installed whenever you see one available.

You should also make sure your passwords are set to something strong that uses a mixture of letters, numbers, and symbols to make it harder to be cracked. Also don’t share your passwords with anyone.

Finally, consider having your smart door lock require a PIN code whenever the door is locked and unlocked using either a voice assistant or a smartphone app.

Providing you are security conscious and put the measures in place to secure your Wi-Fi network, I would certainly consider a smart door lock to be more secure than a regular lock and key.

Can Smart Locks Be Picked?

This will obviously depend on whether the smart door locks sit on top of the original locking mechanism or replaces it completely.

For those that can still be accessed using a physical key, yes there is a chance that they can be picked, but not in the traditional means that your average thief would try and use.

Smart door locks have been picked, but only by lockpicking masters that have spent literally years learning how to do so. They are considered almost impossible to pick.

I don’t think this should be a reason for you to choose one lock over another; I consider even those that fit over your existing lock to be safer than a traditional lock.

On the other hand, the locks that completely replace the locking mechanism and don’t require a key are impossible to pick.

There is simply nothing to pick if there isn’t a hole for a key.