August Smart Lock 3rd Gen vs 4th Gen – Which smart lock is best for your home?

The popularity of August smart locks is not in doubt; they have a retrofit design that makes them easy to install, and they have integrations with the most popular voice assistants. Among them, there is the 3rd and 4th Generations of locks, which both work in similar ways and offer similar benefits.

If you want a good smart lock, August is a major company you cannot ignore due to their high-quality products. The comparison between their 3rd and 4th Gen locks is important, since each caters to different users, and choosing one requires you to know what you need most in your smart lock system.

What are the differences between the August Smart Lock 3rd Gen and 4th Gen?

August Smart Lock 3rd Gen
August Wi-Fi, (4th Generation)
Dimensions (in inches)
3.4 x 3.4 x 2.2 inches
2.8 x 2.8 x 2.75 inches
4 AA batteries 
2 CR123A batteries
Battery life  
6 to 12 months
3 to 6 months
Needs an external bridge
In-built, only 2.4GHz

August Smart Lock 3rd Gen vs. 4th Gen – How do they compare?

Build and size

Between the two lock models, August reduces quite some bulk off the 4th Generation lock through the use of smaller Wi-Fi chipsets that reduce its size by 45%. The 3rd Generation lock is also 20% thicker than the 4th Gen one, which means installing it will result in a large metallic blockade along your front door, unless your door is quite thick in size. This makes the 4th Gen lock a better choice if you want a discreet smart locking system that can fit easily in multiple door sizes.

Battery life

The company behind both locks gives an estimate of the battery life in the 4th Gen lock as ranging from 3 to 6 months, although this depends on the strength of your Wi-Fi signal and your frequency in using the automatic locking mechanism. If your Wi-Fi signal is strong, the battery will not need to work as hard when communicating to the internet. On the other hand, the 3rd Gen lock has a longer battery life ranging from 6 to 12 months. The battery life in the 3rd Gen lock is better compared to the 4th Gen lock.

Z-Wave connectivity

The 3rd Gen lock relies more on Z-Wave connectivity alongside Wi-Fi connectivity, while the 4th Gen lock relies heavily on Wi-Fi connectivity. Because of this, the 4th Gen lock will not function when you unfortunately experience a power outage, which is something to consider if you live in an area that is prone to this. The 3rd Gen lock is a better choice for you if you want alternative connection methods.


The 4th Gen lock can integrate with Siri, Google Assistant, and Amazon Alexa for automated routines and voice commands, and assigns free virtual keys to anyone you want as an additional lock user. Additionally, it will give you a wide range of options when you set notifications for all activity levels at your door, making it easy to customize your security options.

On the other hand, the 3rd Gen lock includes a DoorSense sensor, which alerts you when someone leaves the door unlocked after entering or leaves it open.

The 4th Gen lock has more security options in its sensors, making it a better choice compared to the 3rd Genlock.

August Smart Lock 3rd Gen vs. 4th Gen – A comparison review

August Smart Lock 3rd Gen

The 3rd Gen model package includes everything you will need during installation, although it is worth noting that it is only compatible with single-cylinder deadbolts. Once you install it, you will insert the four AA batteries included in the package, and then connect it to your Wi-Fi network.

The design includes an optional DoorSense module that you stick on the door frame, calibrate it, and then the app will know if the door is locked or unlocked within a short time frame. You will find the companion smartphone app very easy to use, especially in the Guest List screen that allows you to add guests and set up accounts for them.


  • Easy installation
  • Long battery life
  • It can work with Z-Wave hubs offline
  • Does not require the removal of your existing deadbolt


  • Its auto-lock feature can be unreliable at times
  • Large size can cause issues if the fit is too tight
  • Its app does not always display real-time information


View price on Amazon


August Smart Lock 4th Gen


august smart lock

If you want a smart lock that can work with Apple Homekit, Google Assistant, and Amazon Alexa, the 4th Generation August Smart Lock is among the best options to consider without replacing your existing deadbolt. It includes in-built Wi-Fi capabilities and will serve you well if you can afford it due to its smart features and streamlined design.

It has a unique retrofit design that remains true to its roots, but the size is what differentiates it from earlier models. It is 45% smaller than the 3rd Generation lock, measuring 1.8 inches in depth and 2.8 inches in diameter, and will fit in easily with any door design and color.


  • Smaller design that fits in with multiple doors
  • Smooth mechanics
  • Works with Siri, Alexa, and Google Assistant
  • In-built Wi-Fi capabilities


  • Short battery life


View price on Amazon



Both lock systems function very well, with the 3rd Generation lock giving you the functionality of a high-value smart lock at an affordable price, while the 4th Generation takes the benefits of the 3rd Generation lock and improves on them; for instance, reducing the size and adding Wi-Fi remote connectivity.

Verdict: So, which is better? August Smart Lock 3rd Gen or 4th Gen?

The August 4th Gen smart lock is the winner in our review, as it has upgraded security options, a smaller and more convenient design, and increases your overall control over your security through its enhanced connectivity.


Can the August 4th Gen smart lock work without a Wi-Fi connection?

No, because you cannot control it remotely.

What is the battery life in the August 3rd Gen smart lock system?

The average is 6 months, although it could be shorter if you require a lot of force to turn your deadbolt.

Disclaimer: Rated Gadgets is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to We also participates in various other affiliate programs, and we sometimes get a commission through purchases made through our links.

Robinson Wright is a home automation specialist and has helped many modern home developers pick the right gadgets for home automation. According to Wright, most people struggle with particular areas in their home, some would want improved security especially when away from home for a couple of days and others will want to improve power consumption. Homeowner's needs can be fulfilled by investing in smart home gadgets but most importantly is that one must know the functionality that they desire to achieve and then choose a product and technology that would fulfill the need. Robinson Wright runs an appliance enterprise and when not in the field working with his clients, he loves spending time in his workshop testing out the new technologies.

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