Apple HomeKit explained: What is it, and how does it work?

Hot on the heels of the home automation trend, Apple has introduced a new system called HomeKit that will enable you to have wireless and electronic control of your home, household features, activities, appliances, and more.

HomeKit is not yet available for consumers, but you're probably wondering how it works and what exactly it can control. Luckily, Apple outlined much of this through developer sessions at the company's Worldwide Developers Conference.

What is HomeKit?

Home automation

Apple developed the HomeKit framework so it could simplify the current state of home automation.

With HomeKit, Apple essentially created a common language that smart devices (also called accessories) from any manufacturer can understand and support. HomeKit also leverages Siri, Apple's intelligent voice assistance, letting you control smart devices with just your voice.

Imagine having a house chock-full of smart devices (like a light bulb or smoke alarm) from multiple manufacturers (like Honeywell or GE), but they can understand each other and work together. What's more, you can tell these smart devices what to do through Siri on your iOS device.

That's home automation. HomeKit will make the experience consumer-friendly.

Manufacturer support

Manufacturers must add support for HomeKit into their smart devices in order for those devices to be considered HomeKit-enabled. When Apple showed off HomeKit at WWDC in June 2014, it announced partnerships with many manufacturers, including iHome, Haier, Withings, Philips, iDevices, Belkin, Honeywell, and Kwikset.

The first round of Apple HomeKit-compatible products were unveiled earlier this month at CES 2015 in Las Vegas, and Pocket-lint saw everything from smart outlets to smart locks for doors. Examples include: MyQ Smart Garage by Chamberlain, smart sensors by Elgato, iSP5 SmartPlug by iHome, and Insteon's Insteon Hub.

iOS 8

Apple's HomeKit system in iOS 8 will guide you through the process of configuring and naming HomeKit-enabled devices as well as every room in your house. HomeKit provides you with the ability to remotely control your home and all the smart devices inside it. Again, it simplifies home automation.

The idea is you will no longer have to use an individual app to control a single smart device in your home, totaling up to several apps for multiple devices, because iPhone (with HomeKit) will be able to control everything that's compatible.

Apple TV

HomeKit support was quietly added to the Apple TV when iOS 8.1 and Apple TV 7.0.1 rolled out. Some reports have therefore claimed Apple TV will serve as a smart hub of sorts, similar to how Google is positioning the Nest smart thermostat to be a control center. But that's not the full story.

It seems like you'll use Siri through Apple TV to control your HomeKit-compatible devices when away from home, but Apple TV won't be required to control HomeKit in general. Apple told ArsTechnica that Apple TV would act as an intermediary, letting you issue Siri voice commands to your home from a remote location.

That means Apple TV won't really be a smart hub that'll tie your HomeKit devices together but rather an entry point to your local network. The set-top box will simply pass commands to HomeKit devices for you. Your HomeKit devices and Apple TV will need to be signed in to the same Apple ID such functionality to work.

How will HomeKit work?


In the HomeKit system, practically everything - such as a home, room, device, function, setting, etc - must have its own name and be stored in a common database accessible by Siri. That's because Siri has to recognise what it should control whenever you speak a command.

For example, if you own a house and a condo, you will need to assign each home a different name (such as "House" and "Condo"). Every room in your home must have different name as well. Take note that you can have a "Kitchen" in both homes but can't have two "Kitchens" in one home.

All HomeKit-enabled devices in your home, which you should have synced and configured through your iOS device, need their own names too. And every function or service that the device is capable of providing will need a distinct name in HomeKit. So, if you want a cup of coffee, you can name your machine "Coffee pot" and the function "Brew".

Siri will only be able to control your home, rooms, and HomeKit-enabled devices if it can recognise the pre-programmed names you mention during a spoken command.


Those of you who are very tech-savvy could conceivably have hundreds of names in HomeKit for all your rooms, devices, and functions. To make it easier for you to control multiple things at once, Apple has included a grouping feature in HomeKit.

Grouping allows you to, for instance, turn off all the lights in your house with a single spoken command. That means you won't have to ask Siri to shut off every light in every room in every house you own, one by one. Grouping also includes sub-features called Action Sets or Scenes, so you can control more than just multiples of a single type of device.

Imagine you've assigned a scene called "It's bedtime", and various devices and actions are connected to that scene (such as locking your doors, turning off the lights, and setting your alarm clock). When you tell Siri "It's bedtime", HomeKit's grouping feature will alert your doors, lights, and clock to do their respective tasks (in no particular order).


HomeKit features privacy and security layers, according to Apple. It also maintains privacy and prevents smart devices from being misused.

More specifically, HomeKit includes end-to-end encryption between iOS devices and smart devices. The HomeKit API also requires that third-party applications for smart devices in use must run in foreground. This allows you to know exactly which apps are controlling your devices at home.

When will HomeKit release?

HomeKit technically debuted with iOS 8 last autumn, though it has yet to be activated or "launched" by Apple. Some early HomeKit partners, such as third-party accessory makers and manufacturers, have been taking advantage of this wait time to unveil new products that support HomeKit or update existing products.

Most of the new HomeKit-compatible products unveiled at CES aren't yet for sale, as Apple's smart home platform still hasn't launched. We don't know which product will sell first, though most say "soon" and are hinting around springtime.

Will there be an official HomeKit app?

There has been no evidence to indicate a HomeKit app is coming. HomeKit will likely run in the background of iOS 8, controlling your smart devices either directly or indirectly through iOS features like Siri and Geolocation fencing.

What is this "bridged" accessory?

Apple will allow HomeKit to work with non-HomeKit devices that use competing protocols, such as ZigBee or Z-Wave, according to 9to5Mac.

Apple mentioned last year that those home automation products might be able to connect to HomeKit using a hardware “bridge" of some sort, but it hadn't expanded on that concept until recently. A bridged accessory would connect iOS devices to non-HomeKit devices and therefore allow those devices to be controlled by HomeKit's Siri commands.

A bridge can do this by communicating with iOS devices using the HomeKit protocol, and then communicating with non-HomeKit devices using rival protocols. But there are some limitations to a bridged accessory, 9to5Mac has claimed. Apple will not allow home automation devices connecting over Wi-Fi, such as a Nest Thermostat, though it will allow some Bluetooth LE devices to be bridged.

Apple’s restrictions on bridged accessories are apparently security-related. Despite these limitations, Apple will allow bridges to connect to other bridges. Each bridge can connect up to 100 accessories, and they can also be controlled remotely.

Are there any HomeKit alternatives?

Apple's HomeKit is unique in that it doesn't have much stiff competition. Sure, Samsung offers a home automation platform called Samsung Smart Home, but it just debuted earlier this year and is still new.

There's also a nifty platform and app called SmartThings, which turns your smartphone into a remote to control for smart devices in your home and recent rumours have claimed Samsung is considering acquiring SmartThings, which could be interesting for the future.

Apart from Samsung and SmartThings, Apple should keep on eye on Google. The Mountain View-based company already has the potential to both topple HomeKit and dominate home automation, thanks to a company called Nest Labs.


Google acquired Nest Labs, the makers of the Nest smart learning thermostat, for $3.2 billion in January 2014. The high price tag of the acquisition, coupled with Google’s newcomer status to the smart home market, made headlines, and it confirmed the search giant’s interest in home automation.

And then in June 2014, Google announced a new developer program for the Nest division. Called "Works with Nest", the program provides a set of APIs that manufacturers can include in their smart devices in order to let you link and remote control them as well as integrate them with Nest and other Google products.

The thing is - if you watch Nest's YouTube video posted on the Nest developers homepage - you won't hear anything about Google or Android. Google is keeping the Nest brand separate, letting Nest spearhead home automation for the company (which will eventually include rivaling Apple's HomeKit).